ICT

Key Unit competence:

To be able to assemble and disassemble a computer, Identify hardware

issues and fix them and install software

Introductory Activity

1. Observe the image below and answer related questions:

a. What is the task being accomplished by the person in the image above

b. List out any five names of devices found on the figure above

2.1. HARDWARE:

Hardware refers to any physical or tangible part of a computer. The computer

hardware consist of internal and external parts.

A. Internal computer components

Those are all components that are found inside the system unit such as disk

drives, motherboard, processor, power supply, memory, etc.

B. External computer components

External components of a computer also known as peripherals refer to all

externals devices connected to central housing known as the system unit.

They can be input devices, output devices such as the monitor or storage

devices such as a hard drive or flash drive, memory card. Peripherals

devices are connected to the system unit through different ports found on the computer.

2.1.1. Elements of the computer system unit and their roles:

ACTIVITY 2.1:

1.   Open the system unit cover to expose the internal components as shown in Figure below.

                   a. Identify various components inside the system unit

                   b. Briefly state the role of each component identified in a)

The system unit, which houses all the internal components of a computer, has a number of components inside it such as the power supply and them motherboard on which are connected other parts like microprocessor (or

CPU)disk drives, adapter cardsand memory.

Different components of the computer case and their roles are elaborated in the content to follow.

A. Power supply

The power supply is unit is the one which is directly connected to the power outlet through the power cable. The Power Supply Unit (PSU) converts alternating current (AC) from the power outlet to direct current (DC) required by internal computer components.

B. Motherboard

A motherboard also known as circuit board is the main printed circuit board onto which all components of the computer interconnect into one another. It also allows communication of those different parts as it has routes from/to those parts.

Motherboard size varies depending on whether a computer is a desktop or a laptop and the size also varies depending on manufacturers but the devices found on each and their functions don’t vary. A particular desktop computer

looks like in the image below

Figure 2. 3.Motherboard and some of its parts

On the motherboard are connected different devices which are CPU, hard disk, video card, RAM, ROM, expansion slots, data buses, etc.

B.1. Central processing unit (CPU)

The Central Processing Unit (CPU), also known as the processor or microprocessor, is the most important part of the computer which is considered as the “brain” of the computer because all processing activities are carried out inside it.

The processor controls the retrieval, interpretation, and execution of instructions in a computer. It consists of three components namely the Arithmetic and Logic Unit (ALU), the Control Unit (CU) and the memory units, known as registers.

i. The Arithmetic and Logic Unit (ALU)

It is the part of the CPU that performs two main functions, namely arithmetic operations such as addition, subtraction, division, and multiplication and logical operations such as OR, AND, and NOT among others. These two

functions are necessary in the execution of different instructions by the CPU.

ii. The control unit (CU)

The control unit coordinates all processing activities in the CPU as well as

input, storage and output operations. It also performs tasks like controlling, supervising, and overseeing all the activities of the computer. It oversees fetching instructions from the main memory, decoding the instructions in a format the computer can understand, executes the instructions by issuing commands to respective components where action is supposed to be taken

and controlling the transfer of data and information within the available storage space.

iii. Registers

Registers are temporary storage locations located inside the processor that are used to hold data, instructions or information waiting processing or output. There are four types of registers namely: instruction register, accumulator register, address register, and storage register. All the four types of registers store information that is temporarily needed for program execution. The Instruction register holds an instruction before it is converted to machine readable format, the Address register stores the address of the next instruction to be processed, the Accumulator register holds the last processing step of the Arithmetic Logic Unit and the Storage register holds information waiting to be outputted.

B.2. Hard disk

A hard disk also known as hard disk drive (HDD) is a non-volatile computer 

storage device containing magnetic disks or platters with high speed. It is

the term Non-volatile means data and program are retained even when the computer is turned off.

                               Figure 2. 4. Hard Disk

B.3. Video card

Video cards also referred to as graphics cards are components that are connected to the motherboard of a computer system and generates the quality of images on output devices such as screen. Graphic cards have processors or a graphic processing unit and are directly connected to the motherboard which allows it to accept information from the CPU and send output to the monitor.

                                                        Figure 2. 5.VGA card

B.4. Random Access Memory (RAM)

Random access memory (RAM) also known as working storage is used to hold instructions and data needed by the currently running programs. It is referred to as random access because its content can be read directly regardless of the sequence in which it was stored.

RAM is a temporary or volatile storage because its content disappears when the computer is switched off. Therefore, before switching off the computer, it is important to save the work in a device that offers relatively permanent storage facility.

Figure 2. 6. An example of a Random Access Memory

B.5. ROM

Read-Only Memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. As the name indicates; data stored in ROM may only be read and cannot be electronically modified after the manufacture of the memory device. Unlike RAM (Random Access Memory),

ROM is non-volatile, which means it keeps its contents regardless of whether or not it has power.

                    Figure 2. 7.Read Only Memory

B.6. Expansion slot

Expansion slot alternatively referred to as bus slot or port is a connection on the motherboard to which an expansion card can be plugged in order to expand the functionalities of a computer.

                                                 Figure 2. 8. Expansion slot

B.7. Data buses

Data buses are those used to transfer data and instructions between components inside the computer.

                                                                                     Figure 2. 9. Data bus

B.8 Complementary Metal- Oxide Semi Conductor(CMOS) Battery

Complementary Metal- Oxide Semi Conductor(CMOS) is the term usually used to describe the small amount of memory on a computer motherboard that stores the BIOS settings. The basic activities carried out by CMOS is to test the availability of computer basic input and output devices (POST) and make sure no errors exist before loading the operating system.

                                                           Figure 2. 0. CMOS batter

Application activity 2.1

By doing a research using books or the internet:

     1. Explain three types of ports available on a desktop or laptop computer.

         2. Research on the internet about primary, secondary and tertiary

               memory and answer the questions below:

                     a. Which devices are referred to as primary, secondary or tertiary storage devices?

                                b. Why are some of these devices referred to as mass storage devices?

2.1.2. Computer maintenance principles

Activity 2.2:

1. Identify five factors that need to be considered in order to minimize health risks such as RSI

(Repetitive Strain Injuries) and eye strain while using computer

2. Explain why it is not advisable to take food substances and drinks in the computer lab.

 Computers are expensive to acquire. They are also useful to human being because they carry out tasks that are sometimes so difficult. As an important tool in the life of a human, a computer needs to be in good working conditions.

Some computer components can easily get damaged hence need to be handled with care. To protect computers, certain rules, precautions and practices must be obeyed while using computers and their components.

This would help to avoid damage to the computers.

Computer maintenance is the practice of keeping computers in a good state.

Computer maintenance can be carried out on the hardware or software.

The principles of software maintenance can be updates firmware, operating

system, application and data security such as encryption, cache clearing, and

secure deletion. On the hardware side of maintenance there can be cleaning

and properly connecting hardware components, monitoring peripherals,

maintaining cooling and testing individual components for integrity such as

power supplies, RAM modules and the hard disk. On the software side there

is running different tools and software aimed at optimizing the working of a computer.

Below are principles to be followed for computer maintenance:

A. Hardware:

1. Clean dust from the computer.

Computers are some of the most efficient dust collectors. Apart from looking gross and possibly being an allergy hazard, a dusty computer will trap heat, which can reduce its performance and lifespan.

2. Clean up the cabling and everything else

Cables may collect a lot of dust as they are sometimes on the floor. If there

are many peripherals consider cleaning them regularly.

3. Organize the installation disks

Keep memories for different software organized. Don’t mix CDs with memory

sticks or external memories and separate each memory depending on the

type of software stored. Installation software can be Operating systems,

application and utility software.

4. Properly interconnects components

Electronic device components are designed to fit into one another without

using mechanical force, when interconnecting a component into another

requires force this may be an indication of connecting it wrongly and it can

result in the breaking of pins making the whole device unusable.

B. Software

1. Properly switch on/off the computer

To properly switch off the computer gives time for the whole process required

to unload running programs. Switch off the computer when all programs are

closed and use the available computer menu (click on Start then on Shut

down). Never press the power button for switching off the computer. When

programs fail to close use the combination key Ctlr + Alt + Delete to open

the task manager which will help in closing those stubborn programs.

2. Delete unused files and programs

Unused Files and empty folders occupy space and make the computer run

slowly. Delete temporary files, old audios and videos as these occupy bigger

space. Delete also programs that are not used and don’t keep two versions

of the same program if they are not both needed.

3. Back up the data.

A data backup is the result of copying or archiving files and folders for the

purpose of being able to restore them in case of data loss. Data backup

should be done regulary in order to avoid total catastrophe in case there is a

problem with the computer.

4. Run antivirus and scans regularly

Antivirus software is a type of utility software used for scanning and removing

viruses from a computer. Scan so as to avoid computer being infested.

5. Clean up the OS

Disk cleanup is a maintenance utility used to free up space on a hard disk by deleting unnecessary files and Windows components that are no longer in use. This includes temporary internet files, downloaded program files and

files in the recycle bin. The disk clean up procedure will be discussed later.

6. Clean up the software.

Every few months, look through the ‘Add or Remove Programs’ interface

that is found in the control panel. If there’s a software that that is no longer needed, it must be deleted.

7. Update everything

Check for updates for the hardware and software. This includes running

Windows Updates, checking for updated drivers, and checking for software patches.

8. Defragment

Defragmentation is the process of moving file fragments to contiguous

clusters to optimize the storage space and performance.

Application activity 2.2:

1. Explain the importance of computer maintenance

2. Highlighting some routine maintenance practices that need to be carried out in a computer laboratory.

2.1.3. Computer capacity

Activity 2.3:

One day, Peter wanted to borrow films from Jacques who had many but

when he went to Jacques’s home with his flash disk to borrow, the flash

was able to keep only two.

                a. What should Peter do so as to get all the films?

                 b. The two films stored on the flash were of equal size and the flash dish’s size is 1GB. What is the size of each film?

A. Storage size

In digital computers, data is represented using a sequence of bits, bytes and words.

• A bit is a short form for binary digit referring to a single digit which can be either 0 or 1 used to represent any data in digital               computers. In other words, a bit is the smallest unit used to represent data in digital computers.
• A byte is a storage unit capable of representing a single character, such as a letter, number or symbol. Technically, computers  represent any type of data using a sequence of 8 bits. A byte can store 28 or 256 different values, which is sufficient to represent standard ASCII characters (letters, numbers and symbols)
• A word is a unit of data used by a particular processor

Storage capacity also known as storage size refers to the amount of data a storage device can hold. It is measured in kilobytes (KB), megabytes (MB), gigabytes (GB) and terabytes (TB). Since most files contain thousands

of bytes, file sizes are often measured in kilobytes. Larger files, such as images, videos, and audio files, contain millions of bytes and therefore are measured in megabytes. Modern storage devices can store thousands of these files, that is why storage capacity is typically measured in gigabytes or even terabytes for larger memories.

Standard units of measurement used for data storage are in the table below:

A.1. Reading memory/storage size

It is possible to know the size of the memory plugged in a computer or found inside it.

i.Hard disk size

The hard disk size and its different disks can be viewed by going to the

Computer or This PC icon depending on the operating system. These icons

can be found on the desktop or on the startup menu. The window below will appear:

                                  Figure 2. 11. Window to view different disks size

The window above shows that the computer has three disks each disk having respectively 297.48GB, 100 MB and 500 MB. The size of the hard disk is obtained by summing up the size of all the individual disks.

NB: When there is an external memory mounted on the computer, the name of that memory will be displayed in the window used to view the hard disk’s size and the size of that memory can also be viewed in the same window.

ii. RAM size

Proceed through the following steps to obtain basic information regarding

the capacity of primary memory (RAM) installed in the computer

• Press control panel icon
• Through all Control Panel Items select System.

A shortcut can also be used by using Right click on this PC icon and select

properties. The figure below showing information of installed RAM will appear.

Figure 2. 12. Window to view Memory size (and processor speed) in Windows 10

B. Processing speed

Processing speed is defined as the number of cycles per second at which the central processing unit (CPU) of a computer operates and is able to process information. It is measured in megahertz and is essential to the ability of a computer to run applications.

The processing speed is measured in terms of Clock Speed which is measured in gigahertz (GHz), with a higher number equating to a higher clock speed. Faster clock speeds mean that tasks ordered from CPU are completed quicker, making the computer user experience seamless. The processor speed can be viewed using the same window as the one used to view the RAM size.

Application activity 2.3:

           1. If a CD contains 700 MB, how many number of CDs a DVD of 4,7 GB can contain

           2. If a 4MB document is downloaded within 6seconds, what time (in hours) is required to download a 4GB movie?

2.1.4. Identifying and addressing hardware issues

Activity 2.4:

Explain how you would connect both projector and monitor to a single computer.

Computers are built with all security to protect sensitive components and hardware housed inside a casing against any form of dust and other harsh elements. However, some common computer hardware problems occur despite the protection. It’s very crucial to identify and recognize such problems. The following are some of the commonly found hardware related

problems on computers.

2.1.4.1. Common hardware related problems

A. The Check POST test fails

POST stands for “Power OnSelf Test”. This is part of a computer’s startup program used to diagnose the keyboard, random access memory (RAM), disk drives and other hardware to make sure they are working properly. If the POST detects any errors in the hardware, it will either display a text error message on the screen or a series of short and long beeps.

If an error message appears as the computer is booted, read careful the error message and correct it or type the exact error message into a search engine to find more information about it.

B. Blank monitors

A blank monitor is the most common computer problem. Most people who work with computers might have dealt with such non-working blank monitor at least once. In such cases, first and foremost check the supply cord and power systems. Sometimes, the video cable might be loosened. Just push the video cable and place it again.

C. Mouse Problems

The mouse is used for a variety of purposes, such as playing games or opening files and moreover, it facilitates easy navigation. The most common problems related to the mouse include failure to move, connection problems, freezing on the screen or damage to the mouse. Mouse with PS/2 connection are prone to damages in its pins, once such a mouse is not functioning its

pins must be checked for blockage or bending.

D. Jumpy Mouse

A jumpy mouse is just a muted mouse that cannot be scrolled. In case of a track and ball mouse the problem can be solved by opening the ball container, removing the excess debris and cleaning the dirt that lines the rollers. For an optical mouse, eliminate the dust that has collected around the optical sensor.

E. Computer does not recognize USB

In this case, even when the USB is connected, the computer might not be able to recognize it and hence displaying errors like “Device not recognized” This might be due to the USB connector problems or the software malfunctions.

F. Keyboard Problems

Keyboard is a vital part of any computer. It not only allows typing, but also gives commands. Common potential problems with the keyboard include keyboards that will not connect to the computer, stuck keys, broken keyboards or keyboards where the letters end up jumbled.

G. Power Cord Problems

Whether it is a laptop or a desktop, power cords are a vital part of any computer. A laptop can run on batteries for a limited amount of time but then needs the power cord for recharging. The most common problem with the power cord is an improper connection.

H. Motherboard Problems

The motherboard has several parts of the computer including the RAM, BIOS system, mass storage and CPU. The computer motherboard contains several devices, which can create numerous potential problems. Problems with the motherboard range from too little RAM to BIOS problems. Fixing the problems will depend on the specific problem and, in the worst case scenario will require purchasing a new motherboard to fix the problems.

I. Insufficient Memory

Processor-intensive programs also demand a lot of memory. Random access memory (RAM) aides the central processing unit (CPU) by storing instructions linked to common operations. Without enough RAM, software crashes and slowdowns can occur.

2.1.4.2. Checking for hardware problems

Many computer problems are caused by hardware failures or problems with hardware drivers. Windows will usually notify about devices that have problems. Device Manager can be used to check the status of different

hardware devices. The Device Manager which is the Control Panel extension of Microsoft Management Console, provides users an organized, central view of the Windows-recognized hardware attached to a computer. This includes devices like keyboards, hard disk drives, USB devices etc. It sorts out all hardware, listing them on the basis of various criteria and when a device malfunctions or stops working altogether, it immediately notifies the user. Thus it can be used to control devices, enable or disable them, configure them, identify conflicts between devices, and so forth.

To check for window hardware problem using device manager go through this process:

• Open Control Panel
• Click on the Hardware and Sound link for Windows 8 or 10 or Click System and Security for Windows 7.
•  Check under Devices and Printers in Windows 8 and 10, and under System in Windows 7, to find Device Manager.
• Once Device Manager is open, user can view device status, update device drivers, enable or disable devices or do hardware management as shown in the figure below:

Figure 2. 14.Window device manager

Note: Depending on version of Windows, Control Panel is usually available from the Start Menu or the Apps screen.

Application activity 2.4:

    1. a. Identify the common hardware problems that you used to face with while using computer

    b. How can you proceed to solve the problem above?

2.1.5. Assembling a computer & disassembling a computer

Activity 2.5:

1. By searching the internet identify tools used in assembling and disassembling a computer

2. Explain the reasons that may prompt a technician to remove any internal part of a computer

A. Assembling a computer

Assembling a computer is putting together the computer components mainly the internal ones so that they get interconnected and work together.

Assembling a computer can take 20 to 40 minutes provided all parts to assemble are available.

Assembling a computer requires that the technician have simple hand tools kit, such as a screwdriver and a pair of pliers. Always remember to wear a grounding strap when handling any internal components as static electricity can ruin those components. Some computer components to be assembled are shown in the figure below:

Steps to assemble a computer

Step 1: Gather Tools and Supplies

Some tools such as Screwdriver, Wire cutters and strippers, Needle-nosed pliers, Small flashlight, Small container to hold screws, Grounding Strap are helpful to open or fix the screw and need to be made ready before. Also make sure all parts are available and are organized in a way to facilitate identification of which part to fit in the computer case first.

Step 2: Prepare the Case for Assembly

There are three things that need to be considered before assembly

Before assembling consider removing the cover for the optical drive and

make note of the cables pre-installed in the case. These should be front

panel connections for features such as the power switch, audio jacks and USB ports.

Step 3: Install the Motherboard

During motherboard mounting all standoffs need to be installed in the case.

After installation of standoffs it is necessary to checkfor screw holelocations

on the motherboard for exact placement. The next stage requires lowering

the motherboard into the case and aligning with the I/O bezel and installing

the screws. The standoffs and screws are installed in order to prevent

damage to the motherboard.

Step 4: Install Hard Drive

Hard disk drives are usually connected to the motherboard through Enhanced

Integrated Drive Electronics (EIDE), Small Computer System Interface

(SCSI) or Serial Advanced Technology Attachment (SATA) cable interface.

Because with the SATA technology a drive can be detached or attached to

the motherboard while the computer is switched on

The following steps are used to mount the drive into its hole:

1. Find drive bay to install the drive in. If there is a trouble finding a place

to mount the drive consult the case documentation for suggestions.

2. Slide the drive into place until the screw holes on the sides are lined

up with the holes in the case and put/tighten the screws in place.

3. Connect wires that need to be connected

                     Figure 2. 17. Hard drive installation

Step 5: Install Optical Drive

The optical drive is installed in the drive bay.The following steps are used to mount the optical drive into its hole:

1. Slide the drive into the drive bay until the screw holes are lined up 

and the front of the drive is flush with the front of the case. Make

sure that it is orientated correctly.

Step 6: Install the CPU

The CPU is the brain of the computer. It is installed on the motherboard’s appropriate socket.

2. Install the screws and install wires to the right places

To install the CPU, first locate the corner marking that designates pins of the CPU. The second stage require to lift the small metal rod next to the socket and then find the corresponding marking on the CPU socket to insert the CPU so that the markings are lined up. Last push the rod down to lock the processor in place.

Step 7: Install RAM

The RAM is the temporary memory locationthat the processor works from.

Permanently stored data is pulled from disks and stored in RAM while the

processor works with it

The following steps are gone through to mount RAM into its exact position:

• Set the RAM board in the socket. Check to see that the notch in the board is in the correct location
• Press firmly on both ends of the board to set it into the socket. Make sure the tabs lock into place and press the board only when the tab is aligned as not doing so can damage the RAM or even the motherboard.

Step 8: Install the CPU Fan

The CPU fan is a combination of a heat sink and fan together. The unit draws

heat away from the CPU. To install the fan the following steps are followed:

• Firstly Place thermal compound to the CPU following the instructions provided with the compound,
•  Secondly, set the fan assembly on the CPU with mounting tabs aligned,
•  Pull the locking rod down on the fan assembly to lock into place,
• Connect the fan assembly’s power connector to the motherboard.

Note: Failure to apply thermal compound results in insufficient cooling and

can cause damage to the CPU or motherboard.

Step 9: Install Case Fan

The case fan is usually installed on the back panel of the case. To mount the fan do the following:

1. Align the mounting holes by holding the fan to the mounting pad on the inside of the case. The fan needs to be mounted so that it blows air out of the case.

2. Insert the screws from the outside of the case and tighten them

Step 10: Install Power Supply

The following steps are followed to install power supply:

1. Align the mounting holes in the case and power supply.

2. Insert screws and tighten.

Step 11: Connect Cables

                                                              Figure 2. 20. Cable connections

When all of the components installed in the case, it may be possible that there are some parts which may not be supplied with the power. It is important to consult the motherboard manual in order to make sure proper connections are made. There are two kinds of connections, power and data. About power connectors, every device installed needs power. The motherboard has two power connections, connectors specifically for SATA devices (drives) other connectors for running fans and or non-SATA devices.

While data cables connect drives and front panel devices to the motherboard .Incorrect connections can damage components.

Step 12: Wrap-up

Now that the components are completely installed, the last thing to do is to reinstall the side panels on the case. The computer is now ready to be turned on. If the computer has problems starting up, check all component connections and mounting to make sure that everything has been attached correctly. Otherwise consult individual component manuals for specific troubleshooting information if problems persist.

B. Disassembling a desktop computer

Disassembling a computer means disconnecting external and internal components from the system unit. This process involves unplugging, unscrewing and sliding out components depending on the mechanism used to connect to the system unit or mount it onto motherboard. To disassemble a computer, the following process is followed:

1. Disconnect the computer from the power source by unplugging the power cable from power supply unit.

2. Unplug peripheral devices attached to the system unit such as monitor, keyboard, mouse and printer.

3. Open the outer cover of the system unit by unscrewing or sliding it out.

4. Remove the adapter cards by first unscrewing them and gently unplug them off the motherboard

5. Remove the fixed drives such as hard disk and optical (CD/DVD) drives by unscrewing and disconnecting them from power supply unit. Next, disconnect the IDE or SATA interface cable that connects the drive to the motherboard.

6. Remove memory (RAM) modules by pressing the tabs located on both ends down away from the memory slot. Carefully hold the slightly lifted module by the edges and remove it from the motherboard.

7. Remove the power supply unit starting with the power connector to the motherboard, CPU fan, cabinet fan, power buttons and drives if any. Next, unscrew the unit to disconnect it from the system casing

8. Remove the CPU and its fan by first unscrewing the cooler fan from the motherboard.

9. Finally, unscrew the motherboard to unplug it from the system unit casing so as to have an empty shell of the casing

Application activity 2.5

1. Demonstrate how to mount a motherboard using the following guidelines:

• Line it up properly on the chassis, screw and fit it into place.
• Mount the processor, RAM modules and any expansion cards separately.
• Plug in the power cable connector from the power supply unit.
• Connect other internal components onto the board, and then connect the monitor, keyboard and mouse to the system unit.
• Test for power and ensure that internal and external components are initializing correctly during POST (Power-On Self-Test).

2. Do a research and explain five types of expansion cards used on desktop computers.

2.2. SOFTWARE

2.2.1. Software installation principles

Activity 2.6:

       1. Explain the importance of reading the user manual before installing new software.

       2. State three factors you would consider before purchasing application software.

       3. State three hardware requirements to be considered when installing application software.

Software is another part of a computer. It is the invisible part which consists of instructions which operates a computer and executes specific tasks. Software can be classified into two main categories namely system software and application software.

System software is the one that performs a variety of fundamental operations that helps to make computer resources available to the user. It can be divided into Operating systems, Utility software, Firmware and Networking software.

Application software is the one used in a computer in order to perform tasks, functions for the benefits to the user. Application software available in a specific computer depends on the needs of the computer user. For example

one may have VLC to play videos while another may not have it depending on the needs.

The number of computer software or programs installed on a computer is only limited to hardware specifications such as processor type, memory and storage capacity. Once a computer meets recommended specifications, software installations is automatically carried out.

A. System requirement

Before installing computer program whether operating system or application software, there are minimum system specifications that have to be considered in terms of: Memory (RAM) capacity, Free hard disk space, Processor type with speed and Graphics display.

For example, the following are the minimum and recommended system

requirements for the installation of Windows 10 operating system:

• Memory capacity: 1 Gigabyte (GB) of RAM on a 32-bit or 2 GB on 64-bit machine
• Storage space: 16 GB free-disk space on 32-bit or 20 GB on 64-bit machine
• Processor type and speed: 1 Gigahertz (GHz) of CPU Speed
• Graphics card: Microsoft DirectX 9 graphics controller with WDDM driver(Windows Display Driver Model

B. Application software goes with specific operating system

An operating system has specific application software that it is designed to accept, that is due to the fact that an application software needs a working environment that is made ready by an operating system and while developing a program, the developer takes into account the environment provided by that specific operating system. For example Windows operating system can not accept application programs developed for Linux

Application activity 2.6:

1. Discuss various categories of software installed in the computers found in the computer lab of your school.

2. Research on the internet minimum and recommended specification for installing the following software:

c. Latest version of Microsoft Office

d. Latest release of Kaspersky Antivirus

e. Latest Ubuntu Linux

2.2.2. Computer software issues:

Activity 2.7:

At the end of the school term when students were using computers in the school computer lab, every computer worked well but at the beginning of next term they brought from outside different storage devices such as flash disks and other external disks used to copy various documents to the computers. One day when their teacher switched on the computers so as to install some software most of the computers displayed suspected messages.

       a. Discuss what may be the cause of such behaviors.

      b. How the problem can be addressed in the laboratory?

A. Operating System issues

Being the one that directly interacts with the computer hardware through the Operating system kernel, an operating system issue is a serious problem that may make even accessing the computer’s different applications impossible.

The various operating system issues are elaborated in the subsequent content.

i. The computer won’t start

Operating system has the function of managing hardware and other application software resources. A complete damage of an operating system leads a computer to do not start even not function

ii. Abnormally Functioning Operating System

If the operating system or other software is misbehaving, close it forcefully

and reopen it. A virus scan can also help if a reliable anti-virus software is installed.

iii. Operating system is not booting up

When the operating system is not loading, it is a serious problem that requires a fresh reinstall of an OS.

iv. Operating system blue screen of death

A blue screen of death pops up when Windows encounter a critical error and indicates a serious error with a computer device. Incase this occurs, users are prone to losing important data since regular apps don’t normally have a right to save their open data. The main reasons for this issue are:

•  Crashing of a low-level software or drivers
• Drivers updates going wrong
• A faulty hardware
• A virus attack on a system

How to fix the blue screen of death issue:

• Do a system restore which will help undo any recent installed driver.
•  Update device drivers since as time goes by some drivers become incompatible with the regular OS updates which could cause the computer drivers to crash more frequently.
•  Start PC in Safe Mode and troubleshoot any problem from the blue screen details and scan it for viruses since some viruses are known to cause the Blue Screen of death.
• Reinstall the Windows OSif none of the above works.

v. Windows freezes or stops responding

The operating system may sometimes stop responding and freeze. In this

case a cursor may not move, an application may not respond or just a

computer user gets stuck on a certain action. Potential causes of the random

freeze and unresponsiveness on a PC may include:

• Software related issue including malicious software, virus attack and driver related issues,
• Running too many programs at the same time,
•  Memory issues and general hardware failure
• Solutions to windows freezing or stopping to respond
• The best solution is to give the computer some time to process, since it might be handling a complex task that could be taking most of its CPU and RAM
• If giving it more time does not work, then force end the task or program that is not responding by pressing Ctrl + Alt + Del to open the Task Manager. After the Task Manager opens highlight the non-responding program or process and choose “End Task”.
• Reboot the PC by pressing down on the power button until the computer turns off and restart it after a few seconds
• If after rebooting the computer still freezes then reboot the PC in Safe Mode and uninstall any recent driver that might be causing the computer to freeze.
•  Determine if there is a defective piece of hardware that might be causing the device to freeze and replace it immediately. Also check on the computer’s memory such as RAM to know if it needs upgrading.
• When none of the above solutions work a clean install of the Windows Operating System can be considered

vi. Less free storage than before after an operating system upgrade

This happens because files from the previous operating system are still left

in the system in a folder known as “Windows Old”the “Disk Clean-up” tool

can be used to prevent the computer from running slowly.

Steps to delete unnecessary files after an operating system upgrade

• Irrespective of the operating system used, either Windows 7, 8, 8.1, or 10 go to the start then search and type Disk Cleanup
• The disk cleanup app shows, click on it to launch
•  From the Apps interface, select the drive on which the OS is installed which is usually C by default in many PCs.
•  After selecting the drive click Ok and the disk cleanup app will scan for the unnecessary files that can be deleted and present them as a list.

       Figure 2. 21. Disk cleanup selection (C drive)

                         Figure 2. 22. Disk cleanup ready to start

• The disk cleanup then does another search and gives another list now with all the necessary files to delete. From the list select all the unnecessary files taking up on the space including “Previous Windows installations”
•  Click OK and a box asking whether to permanently delete these files will pop up. Click Delete Files.

There are thousands of problems an operating system might encounter. However most of those problems are rare and the existing few have been documented. The various common issue and how they can be solved has been looked atin the above content.

B. Applications issues

Common computer software issues or fault can include the following:

1. Inadequate software performance: This refers to slow system response time and transaction throughput rates.

2. Obsolete software: Software that no longer works due to new hardware or support software changes

3. Inconsistent processing: Software that only works correctly in one environment. This refers to software that has been designed for only one environment and cannot be easily transported and used in another environment.

4. Unreliable results or performance: This means that the software does not deliver consistently correct results and cannot work correctly each time it is used.

5. Incorrect software version being installed on a computer

6. Virus and malware infection on a computer, etc.

The most common way to rectify software issues include uninstalling and reinstalling a software, upgrading the software, running a virus and malware scan. It is also a good practice to check for the manufacturers’ website for patches

C. Malware

Malware are harmful programs or malicious software that are specifically designed to gain access or damage a computer without the user’s knowledge.

They affect the smooth running of a computer system or carry out illegalmactivities such as collecting information from the infected user’s computer.

The categories of harmful programs include viruses, worms, Trojan horses, rootkits, spyware, crimeware, and adware. In this section we will discuss on viruses.

a) Virus

A virus is a self-duplicating computer program or piece of code that is loaded into a computer without the user’s knowledge. Viruses can spread themselves from computer to computer, interfering with data and software.

The source of computer viruses is the internet and storage devices or media.

To Prevent Harmful Programs the following measures can be taken:

i. Install an antivirus program

An antivirus will check for suspicious files and disinfect them or delete them.

Make sure the antivirus is up to date so that it can detect even newly created viruses.

ii. Avoid non-secure sites

Avoid visiting unfamiliar suspicion sites and block special sites that should not be accessed using the computer browser.

iii. Scan emails for viruses

Do not open email attachments unless they are from legitimate known source.

iv. Install anti-spyware software

This is a type of program designed to prevent and detect unwanted spyware program installations.

b) Trojan

Trojan or Trojan Horse is a malicious software that is disguised as legitimate.

Trojan misrepresents itself as useful, routine, or interesting in order to persuade a victim to install it on a computer. Trojans do not replicate themselves and appear harmless but in fact malicious.

c) Worms

A worm is a computer program that sits in the computer memory, duplicates itself continuously until the system runs out of memory and crashes. Worms infect networks by replicating themselves and transmitting their multiple copies to all the nodes connected on the network

d) Rootkit

A rootkit is software used by a hacker to gain constant administrator-level access to a computer or network. It is installed through a stolen password or by exploiting system vulnerabilities without the victim’s consent or knowledge.

Rootkits primarily aim at user-mode applications. Rootkits can completely deactivate or destroy the anti-malware software installed in an infected computer, thus making a rootkit attack difficult to track and eliminate.

When done well, the intrusion can be carefully hidden so that even system administrators are unaware of it.

e) Spyware

Spyware is a software code installed on a computer without user’s knowledge to monitor or supervise user activities.

Spyware can do the following:

• Gather personal information and can transmit it without user’s

• Change computer settings,
• Corrupt windows Registry files,
• Slow down internet connection speeds and the computer itself by taking up memory and space on the computer,
•  Can make a computer to malfunction or totally crash.

f) Adware

The term adware is used to describe a form of malicious software which presents unwanted advertisements to the user of a computer. The advertisements produced by adware are sometimes in the form of a popups or in a window that cannot be closed.

Adware is considered a dangerous programs, its main objective is to collect information about the user,

 to remove the browser‘s restrictions, settings and default search engine. When data collection is complete, 

the current opened program starts to be active, and user gets low-quality sites in response to any request.

g) Crimeware

Crimeware is distinct from spyware and adware. It is designed to commit identity theft through social engineering in order to access a computer user’s financial and retail accounts for the purpose of taking funds from those accounts or completing unauthorized transactions.

Crimeware can have the following impact:

•  Install keystroke loggers to collect sensitive data login and password

          information for online bank accounts.

•  Redirect a user’s web browser to a counterfeit website controlled by the thief even when the user types the website’s proper domain name in the address bar.
• Steal passwords cached on a user’s system.
•  Enable remote access into applications, thus allowing a break into networks for malicious purposes
• Encrypt all data on a computer and require the user to pay a ransom to decrypt it

Application activity 2.7:

1. Using internet search any other common sources of computer virus infection

2. Discuss the various ways a user can acquire a software to use.

3. Demonstrate how to start disk cleanup utility.

2.2.3. Computer software installation

2.2.3.1. Installation of an OS

Activity 2.8:

Suppose your school receives 30 new computers with no installed programs.

a. What is the first program the school ICT teacher or lab technician should firstly install?

b. Explain why?

The term Software Installation means the process of copying installation files of a given program onto the hard disk in a format that allows the computer to run the program. It means putting a computer program on a computer and make it ready to use. Before installing any software read the manufacturer’s installation manual to correctly install programs. 

This manual describes all the procedures and the necessary system requirements for successful installation.

Most programs are installed by downloading the program from online sources.

Programs can be installed from an external storage medium such as a DVD or USB stick.

 If a program is being installed from the disk, the installer will automatically start when a memory is insertedin the DVD drive. What the one doing the installation will have to do is just follow the instructions..

Installation of an Operating System is a fundamental process that starts with identifying minimum or recommended system specifications.

Installation of Windows 10

Like other versions of Microsoft Windows, installation of Window 10 is a three-phase process consisting of: copying files from either bootable USB or CD/DVD, installing features and drivers and configuring settings.

a. Copying files,

At this first stage of installation the all files are moved from either bootable USB or CD/DVD to computer which require installation

b. Installing features and drivers,

At this stage the copied files with respect to their features start to be installed together with the drivers, recall that the role of drivers is to provide a software interface to hardware devices, enabling operating systems and other computer programs to access hardware functions without needing to know precise details about the hardware being used.

c. Configuring settings

This is where installer is asked to choose from available options. This stage of configuration require to be taken carefully as some of the settings once disabled may lead to the malfunctioning of the computer

Step 1: This is the first screen to see while installing Windows 10 using a bootable USB flash drive or DVD.

 Here’s where to choose the Operating System’s language, time and currency format, and input method. 

Once everything is chosen appropriately choose Next to continue

Step 2: In the new window that appears click on Install now

Note: If the repair option is chosen, the Troubleshoot screen where to choose to reset the PC and re-install windows will appear. Therefore, keep or remove the files

Step 3: In the window that appear next enter the Windows product key. 

This can be found online, in the confirmation email so that they can be purchased, or on the DVD packaging.

                             Figure 2. 26. Entering product key window

Step 4: Accept the licence terms. This stage deals with reading software licence terms and condition to install window 10.

Step 5: In the next image, one can choose to upgrade or custom install windows.

In the upgrade option, files, settings and apps are moved to Windows while in custom option these are not moved.

The choice to make will depend on the one installing Windows and what is the needed outcome at the end of the installation.

Figure 2. 27. Windows setup install options (upgrade and custom install)

Step 6: Select the drive to install Windows 10 on. At this step an existing drive can be formatted and used for installation like a new drive can be used for that purpose. Partition is also done.

      Figure 2. 28.Window setup to choose partition for installation

Step 7: Once the partition in which Windows will reside is specified, clicking the Next button moves the installation to the next phase of copying Windows

10 files onto the partition as shown in Figure below:

At this stage after files have been copied configuration is started. During

drivers and features configuration stage, the PC restarts several times.

Step 8: Do personalization of installed Windows

                 Figure 2. 30.Customization before using Windows

Read the settings to customize carefully before turning them on or off

Step 9: Sign in or create a Microsoft account when prompted to do so as shown in the figure below.

      Figure 2. 31. Signing up to Microsoft Account before using Windows

Microsoft account is important as it allows the user to access Windows 10 resources like online emails, cloud and Apps.

Step 10:Let the installer configure Apps before the desktop shown in the figure below is displayed.

       Figure 2. 32. Windows 10 desktop after completing installation

Now Windows 10 is ready to be used. The newly installed window will have on desktop three main items:

 This PC, Network and Recycle bin

Application activity 2.8

Demonstrate and outline steps on how to install various versions of

Microsoft Window operating systems such as window 7,8, etc..

2.2.3.2. Installation of Application software

Activity 2.9:

John bought a computer and connected a flash disk on it to play some music, unfortunately the computer refused to either play the music or open some documents stored on the flash disk but once the flash was connected to the friend’s computer it played and opened the document.

After reading this scenario:

     a. Suggest what should be the problem with John’s computer

    b. How to handle the issue seen in a?

In order to have a computer accomplish a specific task that the computer user want, instead of having only the operating system, a specific software to accomplish a specific task is installed. That software to install is an application software.

A. General guidelines procedure to install application software on the Computer

The first most important step in software installation is to check whether the target system meets the general hardware requirements of the application.

It is also necessary to make sure that the version of the application to be installed corresponds to the Operating System platform running on the computer.

Some computer programs also have software requirements prior to installation. 

Once all the initial requirements have been met, make sure that there are no unnecessary programs running before beginning the installation procedure.

Software installation can be done directly from the Internet or from an installation media

A.1. Installation from media

To install from the disk insert the CD/DVD drive. Once A setup wizard is running simply follow the prompts until the installation process is completed.

In case there is no setup wizard window, open the Explorer and navigate to the optical drive. Double click on either the Autorun or Setup file. For novice users, accept the default values to minimize potential problems during the procedure.

A.2. For installation from the Web

Launch the browser application and download the setupfile to the hard drive.

After completion of the downloading process, run the setup program which is found in the Downloads folder to execute the setup wizard that will handle the automatic installation of the software.

After the installation procedure has been completed and the setup wizard hasterminated, 

reboot the computer before launching the newly installed software.

A.3. Installation of Microsoft office 2013

Most software developers package several programs into a suite with good example being Microsoft Office 2013. 

Go through the following steps:

Step 1: Insert Microsoft Office 2013 DVD or USB installation media into the computer.

 In the licence agreement screen that appears, click the check box with the text “I accept the terms of this agreement”.

              Figure 2. 33. MS Office Licence agreement window

Step 2: Once the Microsoft terms of agreement are accepted, choose whether to upgrade an existing version or custom install a new copy.

Figure 2. 34.Choosing either Upgrade or Customize installation option

If an old version of office is already installed there is an option to upgrade it to a newer version but both the new and the old versions can be kept depending on the user’s choice.

Step 3: To upgrade an existing version of Microsoft Office, click Upgrade.

Make sure the radio button “Remove all previous versions” is selected, and then click Next. 

The installation progress screen shown in the figure fellow.

          Figure 2. 35. Office 2013 installation process

Step 4: Once the installation process is complete, sign in for Microsoft account to get online access to the Microsoft resources like The screen shown in the figure below is displayed to confirm that Office 2013 has successfully been installed.

Figure 2. 36. Microsoft office 2013 home page when firstly opened

Step 5: Open Office 2013 by clicking on the Start button then All apps. The

list of installed Microsoft Office 2013 apps is displayed.

Note:

To install application software successfully there is a need to use an administrator login because with other types of accounts with limited privileges such an installation is not possible.

Sometime once a program is installed into a computer there may be a need for removing them from the computer for different reasons. The process or removing installed application software from computer is known as uninstallation. 

Here below are the procedures followed to uninstall some programs in window 10:

• Open the Start menu
• Select control panel
• Click on uninstall program
• Select the program to remove
•  Click Uninstall
•  Click on the program to uninstall

Application activity 2.9

2. You are provided with Microsoft Office 2016 Installation on DVD or on flash disk. 

Uninstall the current running Microsoft office and Install this provided application on your computer.

End unit assessment

1. Compare safety precautions applied in scientific laboratories such as chemistry, physics and those observed in computer

laboratory

2. Study the motherboard of a computer and perform the following:

a. Identify the CMOS cell battery and RAM mounted on the motherboard

b. Detach and re-attach a CMOS batter and RAM using the following guidelines:

3.      a. Explain briefly the meaning of operating system in the computer system.

          b. Explain three phases taken by operating system during its installation

c.  Discuss any five functions performed by the operating system residing on a computer.

4. State four factors to consider before purchasing application software.

5. Explain why motherboard is the first element to be installed in the process of assembling but the last one to be removed during the process of disassembling?