INTRODUCTION

Computer assembly is a process in which all the internal components of the

computer system are fitted to make the computer functional. The main component
involves cpu, motherboard, memory, disk drives, etc. There is a proper process of
attachment and installation of each and every component. An installation technician
should be competent to disassemble and reassemble the computer system. We will
understand the step by step process of computer assembly and disassembly as a
whole. The assembly and disassembly of the desktop as well as of a laptop
computer is demonstrated.
Tools are an essential part of computer assembly and maintenance. It is also
important to handle the tools carefully and safely. While installing a computer and
its peripherals, you should follow the basic safety guidelines to prevent cuts, burns,
electrical shock, and damage to eyesight. The technician has to take care of the
tools as well as personal safety. Safe working practice helps to prevent injury to
people and damage to computer equipment. We will learn to use various tools
required for installation of a computer and peripherals. We will also understand and
follow the basic safety precautions while handling tools and equipment during the
installation process. For every job, there is a right tool. Use the correct tool
for a task. Skilled use of tools and software makes the job less difficult
and ensures that tasks are performed properly and safely. A tool kit should
contain all the tools necessary to complete hardware repairs. Hardware
tools are grouped into four categories :
i. Esd tools
ii. Hand tools
iii. Cleaning tools
iv. Diagnostic tools
ESD TOOLS
There are two esd tools : The anti-static wrist strap and the
anti-static mat. The anti-static wrist strap protects computer
equipment when grounded to a computer chassis. It is used to prevent
esd damage to computer equipment. The anti-static mat protects
computer equipment by preventing static electricity from accumulating
on the hardware or on the technician.

HAND TOOLS

Most tools used in the computer assembly process are small

hand tools.they are available individually or as part of a
computer repair tool kit. Tool kits range widely in size, quality,
and price.

Electronic cutter
This belongs to the family of pliers and cutter. It is used in
printed circuit board and to cut fine wire. It is sharp enough
and hence cannot damage the other nearby wires.

Precise screwdriver

Screwdriver is a hand held tool, commonly used for inserting

and removing of screw. Screwdriver is made up of a bit and
handle. Bits are detachable according to the use and are
made up of metal, whereas handle is made up of insulating
material.

Different types of precise screw drivers

Screwdrivers are available in different shapes of bit and size. The various
bits can be attached to the screwdriver to work in different fashions. Some
of the bits are mentioned below.

A phillips head screwdriver

It is used to tighten or loosen cross-head screws.

A torx screwdriver

It is used to tighten or loosen screws that have a star- like

depression on the top, a feature that is mainly found on laptops.

Hex driver

A hex driver sometimes called a nut driver is used to tighten or

loosen nuts in the same way that a screwdriver tightens screws.

Wire stripper
It is a portable handheld tool used by workers, especially electricians,
for removing the protective coating of an electric wire in order to replace or
repair the wire. It is also capable of stripping the end portions of an electric
wire in order to connect them to other wires or to terminals. A wire stripper
is often considered an important tool for professional electricians and other
related personnel.

Crimper

This is used for the joining of stripped wire and special connector.
Stripped wire is inserted through the correctly sized opening of the
connector. And then crimper is used to tightly squeeze the opening
against the wire.

Tweezers

These are used to manipulate small parts.

Punch down tool

It is used to terminate a wire into termination blocks. Some cable

connectors must be connected to cables using a punch down
tool.

CLEANING TOOLS

Soft lint-free cloth

It used to clean different computer components without

scratching or leaving debris.

Compressed air

It used to blow away dust and debris from different computer

parts without touching the components.

Cable ties

They are used to bundle cables neatly inside and outside of a

computer.

Parts organiser

It used to hold screws, jumpers, fastners, and other small

parts and prevent them from getting mixed up together.

Diagnostic tools

Digital multimeter

It is used to test the integrity of circuits and the quality of

electricity in computer components. A digital multimeter displays
the information on an lcd or led.

Loopback adapter

It is also known as a loopback plug and is used to test the

basic functionality of computer ports. The adapter is specific
to the port that you want to test.

Toner probe

It is a two-part tool. The toner part is connected to a cable at

one end using specific adapters such as an rj-45, coaxial, or
metal clips. The toner generates a tone that travels the length
of the cable. The probe part traces the cable. When the probe is
in near proximity to the cable to which the toner is attached, the
tone can be heard through a speaker in the probe.

SAFETY TOOLS

While installing computer and peripherals, you should follow

the basic safety guidelines to prevent cuts, burns, electrical
shock, and damage to eyesight. As a best practice, make sure
that a ire extinguisher and first aid kits are available in case of
fire or injury. Place the cables in conduit or cable trays to
prevent hazards. Some basic safety precautions to be followed
when working on a computer are as below:

Electrical safety

Follow electrical safety guidelines to prevent electrical fires and

injuries. Power supplies and crt monitors contain high voltage.

Precautions

Do not wear the anti-static wrist strap when repairing power

supplies or crt monitors. Some components retain a high
voltage even after the printer is turned off. Check the printer
manual for the location of high- voltage components.

COMPUTER ASSEMBLING AND DISSEMBLING

Computer assembly is an essential job of an installation

technician. The technician has to work in a logical, methodical
manner while handling various computer components and
peripherals. The technician can improve the computer assembly
skills with practice. Computer assembly is a process in which all
the internal components required for the computer system are
fitted so as to make the computer functional. There is a proper
sequence of attachment of each and every component into the
computer system. To establish proper connectivity, one has to
use the tools. Proper handling of tools is also required by the
technician. It is required that students learn the steps of
installation of each component. The main component involves
installing cpu, motherboard, drives, video, graphics card, sound
card, modem and adapter, and connectors, and system panel
connector.

Computer assembly

As we know, computer assembly is a systematic process. First,

arrange the computer parts. The sequence for assembly and
working of the computer listed below is as:

 Open the case.

 Install the power supply.

 Attach the components to the motherboard.

 Install the motherboard.

  Install internal drives.

 Connect all internal cables.

 Install motherboard power connections

 Connect external cables to the computer.

 Boot the computer for the first time.

Material required

 Computer case, with power supply installed

 Motherboard

 Cpu

 Heat sink/fan assembly

 Thermal compound

 Ram module(s)

 Motherboard standoffs and screws

 Anti-static wrist strap and anti-static mat

 Tool kit

Procedure

Step 1: Open the case

 The first step in assembling a computer is to open the computer

case. There are different methods for opening cases.

 The computer comes with various types of cabinets. The method

for opening the case is different based on the manufacturer.

 To open the case, first remove the screws of the left side cover and
slide the side cover

Step 2 : Install the power supply

The next step is to install a power supply. There are usually four screws
that attach the power supply to the case. Power supplies have fans that
can vibrate and loosen screws that are not secured. When installing a
power supply, make sure that all of the screws are used and that they are
properly tightened.

 Insert the power supply into the case.

 Align the holes in the power supply with the holes in the case.

 Secure the power supply to the case using the proper screws.

Step 3: Attach the components to motherboard

The motherboard has to be prepared before its installation. To
prepare the motherboard, you first need to install the cpu, then
the heat sink on the cpu and cpu fan.

Cpu

The cpu and motherboard are sensitive to electrostatic

discharge. So place them on a grounded anti-static mat and
wear an anti-static wrist strap while handling the cpu. When
handling a cpu, do not touch the cpu contacts at any point. The
cpu is secured to the socket on the motherboard with a
locking assembly. Thermal compound which is used to conduct
heat away from the cpu is applied on the top of cpu. In case of
an old cpu, first clean the top of the cpu, and then apply the
thermal compound. Clean the top of the cpu and the base of
the heat sink with isopropyl alcohol and a lint-free cloth. This
removes the old thermal compound. Then apply a new layer of
thermal compound.

Heat sink and fan assembly

Heat sink and fan assembly is a two-part cooling device. The

heat sink draws heat away from the cpu. The fan moves the
heat away from the heat sink. The assembly has a 3-pin power
connector.
To install a cpu and heat sink and fan assembly, follow these
steps:
 First, open the cpu load plate. Align the cpu orientation so
that the notches on the cpu are aligned with the
orientation keys on cpu socket.
 Place the cpu gently into the socket.
 Close the cpu load plate.
 Close the load lever.
 Apply a small amount of thermal compound to top of
the cpu.
 Screw the cpu fan on the heat sink.
 Align the heat sink and fan assembly with the holes
on the motherboard.
 Place the assembly onto the cpu socket carefully.
 Screw the assembly on the motherboard.
 Connect the assembly power cable to the cpu fan
connector on the motherboard.
 Installation of ram

It is better to install the ram first on the motherboard and then fix the
motherboard in the case. To install ram, first ensure its compatibility with
the motherboard. If ddr3 is mentioned on the motherboard, then ddr3 ram
may be fixed in the memory slot. To install ram, follow these steps.

 Press down the side locks of the memory slot. Align the notches on
the ram module to the keys in the slot and press down on both ends of
ram module until the side lock gets locked.

 Make sure that the side tabs have locked the ram module.

 Repeat the above steps to install additional ram modules.

Step 4: Install motherboard

After preparing the motherboard, you can install the computer case. Plastic
and metal standoffs are used to mount the motherboard and to prevent
it from touching the metal portions of the case. To install the
motherboard, follow these steps:

 Lay the motherboard over the standoffs to mount it on the holes.

 Align the screw holes of the motherboard with the standoffs.

 Then screw the board using a standard screwdriver.

 Tighten all the motherboard screws.

 Connect the 4-pin atx power connector from the power supply to the
motherboard.

Step 5: Install internal drives

Hard drive

The hard drive is the device which stores all the data. It is 3.5
inch wide and needs to be mounted so that access to the
cable connections on the back is gained. Drives that are
installed in internal bays are called internal drives. A hard disk
drive (hdd) is an example of an internal drive. To install hdd,
follow these steps:

 Position the hdd so that it aligns with the 3.5 inch drive
bay.

 Insert the hdd into the drive bay so that the screw holes
in the drive line up with the screw holes in the case.

 Secure the hdd to the case using proper screws.

 Optical drive

 Position the optical drive so that it aligns with the 5.25

inch drive bay.

 Insert the optical drive into the drive bay so that the optical
drive screw holes align with the screw holes in the case.

 Secure the optical drive to the case using the proper

screws.

 Connect the power cable coming from the smps to the

power socket of optical drive.

 Connect sata data cable from optical drive socket to the

motherboard socket.

Step 6: Connect all internal cables

Power cables are used to distribute electricity from the power

supply to the motherboard and other components. Data cables
transmit data between the motherboard and storage devices,
such as hard drives.

Step 7: Install motherboard power connections

Just like other components, motherboards require power to operate. The

advanced technology extended (atx) main power connector will have
either 20 or 24 pins. The power supply may also have a 4-pin or 6-pin
auxiliary (aux) power connector that connects to the motherboard. A
20-pin connector will work in a motherboard with a 24-pin socket. Follow
these steps for motherboard power cable installation:

 Align the 20-pin atx power connector with the socket on the
motherboard.

 Gently press down on the connector until the clip clicks into place.

 Align the 4-pin aux power connector with the socket on the
motherboard.

 Gently press down on the connector until the clip clicks into place.

Sata power connectors

Sata power connectors use a 15-pin connector. Serial advanced technology

attachment (sata) power connectors are used to connect to hard disk drives,
optical drives, or any devices that have a sata power socket.

Step 8: Connect external cables to the computer setting up the computer

system involves the complete process of establishing the proper
connectivity of various parts of the computer system input and
Output devices, connectivity of computer with the surge power supply.
Reattach the side panels to the case. The process of connecting the
external cables given below:

Locate the monitor cable

Locate the two power cable and one vga cable or monitor cable. The vga
cable is used to connect to monitor and another point on to the back side
of the cabinet. If you are having trouble finding these, refer to the
instruction manual of or the computer. You can skip to ‘step 3’, in case of
all-in-one computer that is built into the monitor.

Connecting monitor

Connect one end of the cable to the monitor port on the back
of the computer case and the other end to the monitor. In case of
vga cable, tighten the screws on the monitor cable to secure it.
The cables will only fit in a specific way. If the cable does not
fit, do not force it, otherwise the connectors might get
damaged. Make sure the plug aligns with the port, then
connect it. So, first identify all the cables, ports, and
connectors.

Connecting keyboard

Unpack the keyboard and determine whether it uses a usb

(rectangular) connector or a ps/2 (round) connector. If they have colour
coded plugs that are light green and lavender, plug them into the
corresponding colour-coded ports, it is more likely if they use round ps/2
connectors. If it uses a usb connector, plug it into any of the usb ports on the
back of the computer.

Connecting mouse

Unpack the mouse and determine whether it uses a usb or ps/2

connector. If it uses a usb connector, plug it into any of the usb ports on
the back of the computer. If it uses a ps/2 connector, plug it into the
green mouse port on the back of the computer. In case of wireless mouse
or keyboard, connect a bluetooth dongle (usb adapter) in one of the usb
ports of the computer. However, it is not necessary to connect an
adapter for the modern computers which have built-in bluetooth.

Connecting headphones or speakers, and microphone

Connect the external speakers or headphones, to computer’s audio port

(either on the front or back of the computer case). The modern computers
have colour- coded ports. Speakers or headphones connect to the green
port, and microphones connect to the pink port. The blue port is the
line-in, which can be used with other types of devices. They can be also
connected to the usb port. Some speakers, headphones, and microphones
have usb connectors instead of the usual audio plug. Connect them to any
usb port. Some computers have speakers or microphones built into the
monitor.

Connect the computer to a power supply

Locate the two power supply cables that came with the computer. Plug
the first power supply cable into the back of the computer case and then
into a surge protector. Then, using the other cable, connect the monitor
to the surge protector. It is better to use an uninterruptable power supply
(ups), which acts as a surge protector and provides the back up when the
power goes off.

Plug the surge protector

Plug the surge protector into a wall outlet after finishing the
connectivity of all the parts and peripherals, plug the surge
protector into the main power supply. You may also need to
turn on the surge protector if it has a power switch.

Connecting printer, scanner, webcam

To connect the peripherals such as printer, scanner, webcam,

identify the respective connectors of the cable and port on the
cabinet. Plug in the connectors of these peripherals in respective
ports. Correctly plugging in will recognize the peripherals as
they are plug and play devices.

It may be required to install their software drivers for them to function

properly. Use the instructions included with the device to install them if
necessary. Installation of peripherals is optional, and it be can added at any
time; it may not be required during the initial setup of your computer.
Checklist the following before starting the computer :
 Vga cable of monitor is connected to the cabinet
Or not.
 Power cable of monitor and cabinet has been plugged into the ups
power output socket. Make sure monitor is connected to the power
supply or not.
 Keyboard and mouse both are connected to their
Proper ports.
Step 9: Starting the computer

To start the computer, it is necessary to follow the correct sequence to start

up. Now push the power button on the cpu to start the computer. Practically
when we start our vehicle, we always check that the light or air conditioner
(ac) is off. Otherwise it will consume more power compared to normal start
up.

Always remember that the first step is to push power button

of the cpu than the monitor’s. Because the monitor consumes
more electricity when powered. An operating system or system
software like window or linux will start loading and the home
window will appear. Now your computer is ready to use.

Computer disassembly

Disassembly is the process of breaking down a device into

separate parts. Disassembly of any device is required to
determine a problem, to replace a part, or take the parts and
use them in another device. A computer is also an electronic
device which requires disassembly for such issues. For
example, if a ram gets dysfunctional in a computer, then it
requires disassembling the computer to take out the
dysfunctional ram and replace it with new ram chips. As we
know, computers have standard internal components, but the
way of placement may vary as per the pc tower case and
different brands of computer. The best way is to refer to the
manufacturer instructions manual. But in general there is a
standard process of computer disassembly, which is
demonstrated in this session. Just like computer assembly, the
disassembly is a standard process. The process involves
unplugging of all the cords and cables connecting a
component to other components, then removing the part from
the case or frame. Components can be attached to the case
with special clips, screws, or by insertion into a holder. A small
amount of force is required to remove each part of the
computer system.

Material required

 One working pc

 An anti-static wrist strap

 An anti-static mat
  Anti-static bags of various sizes

 Technician’s toolkit

 A plastic cup or box to organize screws, nuts, and bolts

Procedure

The disassembly procedure of computer is demonstrated

As below.

Step 1: Unplugging

 Unplug the power cord from the pc and from the wall socket to prevent
any injuries and damage of the pc from electrostatic discharge (esd).

 Unplug all the peripherals attached to the computer, such as the

keyboard, mouse, monitor, headphones, and any external drives.

 Wear a grounding strap to discharge any static

Electricity.

Step 2: Open the case

The computer comes with various types of cabinets. The

methods of opening the case are different based on the
manufacturer.

 To open the case, first remove the screws of the left side
cover and slide the side cover.

 Pull the latch to release the side panel. Then lift the side
cover out from the chassis.
To remember connectivity of internal cables, take the
photographs of internal circuitry. It will help to assemble back the
system.

Step 3: Disconnect all the connectors

Disconnect all the connectors connected to the motherboard.
These include sata power cable and data cable of hdd as well
as sata cable of optical drive.

Step 4: Remove the fan

Remove the fan now. Most computers have two fans — the system fan
and cpu fan. The system fan is located at the back side of the
computer to blow air into the computer. The cpu fan is located on top of
the cpu heat sink. The fans and its connectors are labelled with their
names.
To remove the system fan, first, disconnect its connector from the
motherboard. Then, unscrew it from the outside of the back of the
case and lift the fan out of the system.
To remove the cpu fan from the heat sink, first, disconnect its
connector from the motherboard. Then remove the four screws securing
it.

Step 5: Remove the power supply

The power supply is connected to the motherboard by a 20-pin connector
and 4-pin connector. It is also connected to hard disk drive and the optical
drive. Firstly, disconnect hard disk drive and the optical drive connectors
from the motherboard.
 Disconnect the power cable of the hard disk and optical drive which
connects to the smps.
 Remove the screws that secure the power supply
Unit to the chassis.
 Carefully lift the power supply out of the chassis.

Step 6: Removing hdd and optical drive

 Remove the sata cable connecting to the hdd and motherboard.

 Then unscrew the four screws securing it in place and pull out the
hdd

Step 7 : Remove ram (random access memory)

Ram allows for the transfer of information to and from the cpu. Computer
runs fast with more ram. Most computers have four ram slots, and two
ram chips. To remove the ram, push down on both tabs holding the ram in
place, which are located at both ends of the ram. It will cause the module
to pop up for easy removal.

Step 8: Remove expansion cards

The modern motherboards are integrated with the audio, video and
network cards. However, if your computer has the expansion card, insert
into the expansions slot to increase the functionality. The expansion card is
screwed with a single screw on top of expansion card slot.

 To remove the expansion cards, disconnect the cables attached to it.

 Remove the screws securing the cards in the slots.

 Carefully take out the cards in the slots.

Step 9: Remove motherboard

Every part of the computer is attached to the motherboard. The cpu,
ram, and expansion cards are directly attached to the motherboard. To
remove the motherboard, disconnect all the cables from the motherboard.
It has seven screws holding it to the frame. Remove these screws and
then lift the motherboard out of the frame.

Step 10: Reassemble the components

 Identify every component and take its photograph.

 After identification of each component, put all the components back in their
place and ensure that all cables and wires are connected at the right place to
avoid further troubleshooting.

 Close the case and put the screws back in their place.

 Lastly, connect every external device such as the keyboard,

mouse, monitor, etc., and turn on the computer to see if everything is
working fine after assemble.

ASSEMBLING OF LAPTOP
Material required
 Laptop
 Mini screwdriver
 Anti-static wrist strap
 Magnifying glass

Procedure

Step 1: Keep track of screws

There are several types of small screws that are used throughout
the laptop. Place these in small envelopes and write the
component name on the envelope. Be organized and keep
track of all the screws. We have to figure out how to remove
the back panel.

Step 2: Installation of processor

First component to be installed is the processor. Take extreme

care not to touch the pins in the socket during the process.

Step 3: Pop in the video card

First, find the baggie with three larger silver screws and two small black
screws to install the graphics card. Hold the card at about a 30-degree angle
as you insert its edge connector into the video-card slot near the center of
the motherboard. Press the card in and downward, and then use the two
small black screws to secure it in place.

Step 4: Set up the drive

The motherboard sata connectors are along the front, right edge, and under
the lip of the laptop’s shell. Drop the drive into place and then carefully
use your thumb to push the drive into the sata connectors. Now use the
remaining two screws to secure the drive in place.

Step 5: Add memory

To install memory, locate the memory slots on the motherboard. Align the
notches on the memory module with the ridge in the slot. Firmly push the
module until the clips on the side of the slot snap into place.

Step 6: Final assembly

Now that all the hardware components are installed, find the
four screws you removed from the ace door, slide the door
back into place, and replace the screws. To prepare for power
up, pop in the notebook’s battery pack, connect the power brick
and plug it into a wall outlet. Finally, open the laptop’s cover with
one hand, use your other hand to press the power button.

DISASSEMBLY OF LAPTOP
Procedure

Step 1: Removal of battery

Start the disassembly process by removing the battery.

Remove one screw securing the optical cd/dvd drive. Pull out
the optical drive and remove it. Remove all the screws
securing the bottom case. There are two screws hidden under
the two laptop bottom feet. Remove the bottom screws. Peel off
the bottom from the case to access the hidden screws.
Remove the hidden screws from both sides of the notebook.

Step 2: Separation of palm rest

Using a plastic case opener, separate the palm rest from the
bottom case.

Step 3: Removal of bottom case

Turn the notebook upside down and remove the bottom case.
Step 4: Disconnecting the hard drive cable from the
motherboard
Remove the three screws fixing the hard drive bracket to the case.
Disconnect the hard drive cable from the motherboard.

Step 5: Remove the hard drive

Remove the hard drive assembly from the notebook. If you are going to
replace it with another hard drive or ssd, you will have to transfer the
mounting bracket and sata cable.

Step 6: Removal of ram

A notebook pc motherboard has two memory slots. Remove both ram

modules if necessary.

Step 7: Disconnection of cable

Remove the one screw fixing the usb led status board. Disconnect the
cable from the motherboard.

Step 8: Removal of usb led status board

Remove the usb led status board.

Step 9: Removal of screw fixing the optical cd/ dvd drive

connector board

Remove the one screw fixing the optical cd/dvd drive

connector board. Disconnect the cable from the motherboard.

Step 10: Removal of the cooling fan

Remove the two screws fastening the cooling fan to the case. Unplug the fan
cable from the motherboard and remove the cooling fan.

Step 11: Removal of dc power jack

In a notebook pc, the dc power jack is mounted under the hinge.

Remove it. Disconnect the wi-fi antenna cable from the wireless
card. Disconnect the dc power jack harness from the
motherboard. Move all cables aside and remove the two screws
from the display hinge. Open up the hinge and remove the dc
power jack.

Step 12: Removal of motherboard

Separate the motherboard from the top case and remove it. The
other side of the motherboard.

In a notebook pcs, the keyboard is permanently attached to the top case

with rivets. When the keyboard fails, it is necessary to replace the top case.
The touchpad is glued to the top case but the touchpad button case can be
removed.

Laptop lcd screen removal

Procedure

It is possible to disassemble the lcd screen of a laptop independently.

Previous steps are not required for disassembling the display, you only
need to disconnect the battery before you start.

Step 1: Separate the display bezel from the back cover. You will have to
wiggle the bezel to unfasten it from the cover. Start on the top and move
to the sides for the display assembly.

Step 2: On the bottom, the bezel is attached to the lcd screen with
adhesive tape. Carefully separate it from the screen.

Step 3: Remove the bezel completely.

Step 4: Remove the four screws securing the lcd screen to the side
brackets.

Step 5: Separate lcd screen from the back cover and place
it the front side down on the keyboard.
Step 6: Now you can access the video cable connector.

Step 7: Peel off the grounding tape from the screen.

Step 8: Peel off the clear tape securing the connection and
unplug the video cable from the screen.
Step 9: Remove the lcd screen completely and replace if
necessary.

Step 10: You can find a new lcd screen using the model
number from the original one.
OPERATING SYSTEM
An operating system (os) is software that runs on a computer. It
manages all other applications and programs in a computer, and a boot
program loads it into the computer. The os enables applications to
interact with a computer’s hardware.
Application programs request services from the operating system through a
designated application program interface (api). The kernel is the software that
contains the operating system’s core components. Every computer must have at
least one operating system installed to run other programs. Windows, linux,
and android are operating systems. They let you use programs like ms office,
notepad, and games on your computer or phone. You also need an operating
system on your computer to run basic programs like internet browsers.
An operating system (os) is essential for the functioning of any computer system.
Here are the key reasons why using an operating system is crucial:
1. Resource management
The os manages the system’s hardware and software resources, including the
cpu, memory, storage, and peripheral devices. It ensures these resources are
allocated efficiently and fairly among all running applications.
2. User interface
Operating systems provide a user interface (ui), which can be graphical (gui) or
command-line (cli). This interface allows users to interact with the computer
system, execute programs, manage files, and perform various tasks efficiently.
3. Application support
The os provides a stable and consistent environment for applications to run. It
offers essential services and apis (application programming interfaces) that
developers use to build and execute software applications.
4. File management
The os manages files on storage devices, organizing data into directories and
files. It provides mechanisms for reading, writing, and accessing files, ensuring
data integrity and security.
5. Security and access control
Operating systems implement security measures to protect data and system
resources. They manage user accounts, permissions, and access controls to
ensure that only authorized users can access certain resources and perform
specific actions.
6. Process management
The os executes multiple processes (programs) simultaneously. It schedules
processes, allocates cpu time, and manages multitasking to ensure the system
runs smoothly and efficiently.
7.device management
The os manages communication with peripheral devices like printers, scanners,
and external drives. It provides device drivers and handles input/output
operations, ensuring that devices function correctly with the system.
8. Networking
Modern operating systems include networking capabilities that allow computers to
connect to local networks and the internet. They manage network connections,
data transfer, and communication protocols.
9. Error handling
The os detects and responds to hardware and software errors. It provides error
reporting and recovery mechanisms, ensuring system stability and reliability.
10. Support for multitasking
Operating systems enable multitasking, allowing multiple applications to run
simultaneously. This increases productivity and allows users to perform various
tasks concurrently.
Using an operating system simplifies the complexity of managing computer
hardware and software.
It provides a user-friendly environment, essential services, and robust security,
making it indispensable for modern computing.
Functions of operating system
Operating systems (os) perform several essential functions to ensure computers
and devices run smoothly:
 Memory management: The os allocates and deallocates memory as needed
for various programs, ensuring they can run simultaneously without
interference.
 Processor management: It manages the cpu’s time and resources, choosing
which processes get cpu time and optimizing processor use.
 Device management: The operating system handles connections to input and
output devices using device drivers. It assigns devices to processes and
tracks their status.
 File management: The operating system does jobs like making, deleting,
moving, and saving files while keeping them safe.
 Storage management: The os accesses and organizes files and directories,
optimizes storage device use, and ensures efficient data retrieval.
 Security: Oss use firewalls and other security measures to prevent
unauthorized access and monitor system activities to block threats.
 Performance monitoring: The os tracks all system activities, including
resource usage and errors, to ensure the system operates efficiently.
 Error detection: It continuously scans for errors and threats, protecting the
system and alerting users to potential problems.
 Software and user coordination: The os ensures that hardware and software
work together smoothly for optimal user interaction.
Modern operating systems also include advanced features such as:
 Virtualization support: They allow multiple virtual machines to operate on a
single physical machine, optimizing resource use.
 Cloud integration: Oss now seamlessly connect to cloud services, allowing for
easy data synchronization and backup across devices.
 Energy management: Especially important in mobile devices, oss manage
hardware resource use and background processes to extend battery life.
 Advanced security: Features like biometric authentication, encryption, and
continuous security updates help protect against new threats.
 Automated updates: Operating systems can update and maintain themselves,
keeping systems secure and up-to-date without manual effort.
 Iot support: Operating systems manage various internet of things devices and
their interactions.
 Ai and machine learning: Modern oss incorporate ai and machine learning for
better analytics, personalization, and user engagement.
These capabilities highlight how operating systems continuously evolve to meet
new technological needs and enhance user experiences.
Popular operating systems
Some of the most popular operating systems in use today include:
 Windows: Windows is the most popular desktop operating system, used by
over 1 billion users worldwide. It has a wide range of features and
applications, including the office suite, gaming, and productivity tools.
 Macos: Macos is the desktop operating system used by apple mac computers.
Users appreciate its clean, user-friendly interface, making it popular among
creative professionals.
 Linux: Linux is an open-source operating system. It is available for free, and
users can customize it to meet their specific needs. Developers, businesses,
and individuals who prefer an open-source, customizable operating system
use it.
 Ios: Ios is the mobile operating system used by apple iphones and ipads. Its
reputation arises from its user-friendly interface, close integration with
apple’s hardware and software, and robust security features.
 Android: Android is the most popular mobile operating system, used by over 2
billion users worldwide. Its reputation stems from its open-source nature,
which offers customization options and compatibility with a wide range of
devices.
Advantages of operating system
There are several advantages of operating systems. We have listed some of them
below:
1. Ensuring correct and efficient use of the computer’s hardware.

2. Allowing different applications to run concurrently.

3. Managing files and folders.

4. Providing a user interface.

5. Managing security.

6. Managing resources.
7. Managing printing.

8. Providing a platform for software development.

DEVICE DRIVER
A device driver is a particular form of software application that allows one
hardware device (such as a personal computer) to interact with another hardware
device (such as a printer). A device driver may also be called a software driver.
Drivers facilitate communication between an operating system and a peripheral
hardware device. Each driver contains knowledge about a particular hardware
device or software interface that other programs including the underlying
operating system (os) does not have. In the past, device drivers were written for
specific operating systems and specific hardware peripherals. If a peripheral
device was not recognized by their computer's os, the end user had to locate and
manually install the right driver.
Today, most operating systems include a library of plug-n-play drivers that allows
peripheral hardware to connect automatically with an operating system. This
approach also has the advantage of allowing programmers to write high-level
application code without needing to know what hardware their code will run on.
FIREWALL CONFIGURATION
A firewall is a network security that is configured to enable an organization
protects its data from leakage and cyberattacks.
Proper firewall configuration is essential, as default features may not provide
maximum protection against a cyberattack.
WHAT ARE JUNK FILES?
Junk files are temporary files created so your computer or phone can perform
specific tasks and that are now no longer needed. At one time, these files files
were helpful, because programs, applications, and operating systems need to
create temporary files to execute computing tasks. But after serving their
purpose, these files becomes useless junk.
Here are some common types of junk file you will find on your computer:
 Temporary internet files(eg. Videos or audios)
 Temporary system files(eg files created and stored to launch startup
programs)
 Installer files(files created when you install programs and apps on your
device)
 Thumbnails(these are image previews displayed when you visit websites with
images, they help the images load faster)
 Deleted/recycle bin files(those traces that remain after deleting or removing a
file)
How do we remove junk files?
Here are the best ways to remove junk files off your computer:
1. Perform a scan
2. Delete unwanted applications
3. Removing temporary files
After removing unwanted files, there’s need to backup your files.
DATA BACKUP AND RECOVERY
What is backup and recovery?
Backup and recovery is the process of duplicating data and storing it in a secure place
in case of loss or damage, and then restoring that data to a location the original one
or a safe alternative so it can be used again in operations. Ideally, this backup copy
(often called a snapshot) is immutable meaning it cannot be altered after it is created
to protect against mutations such as ransomware. Backup and recovery is also a
category of onsite and cloud-based technology solutions that automate and support
this process, enabling organizations to protect and retain their data for business and
compliance reasons. There are 3 main categories of backups:
 Full backups
This type of backup makes a copy of all data to a storage device, such as a disk or
tape. The primary advantage of making a full backup is that a complete copy of
all data is available with a single set of media. These backups can take many hours,
even days, depending on the amount of data being saved. The more modern a data
management solution is, the fewer full backups it must perform, and when it does, the
faster it goes.
 Incremental backup
This type of backup will result in copying only the data that has changed since the
last backup operation of any type. The advantage of an incremental backup is
that it copies smaller amount of data than a full backup.
 Differential backup
This is similar to an incremental backup the first time it is performed, in that it will
copy all data changed from the previous backup. However, each time it is run
afterwards, it will continue to copy all data changed since the previous full
backup. The advantage of this type of backup is that it stores more backed up
data than an incremental backup on subsequent operations.
What is the difference between backup and recovery? The key difference
between backup and recovery is that the backup process is how you save and protect
your production data and safely store it away so you have it for a later time, when you
might need to use it. Recovery is the process whereby you retrieve and restore that
backup data to your production systems to avoid downtime. Reliable backups and fast
recovery together ensure business continuity and business resilience.

What are the types of data recovery?

The amount of data organizations create, capture, and store has skyrocketed over the
last decade. And analysts anticipate the amount of new data generated will grow at
more than 50% compounded annually.
Because enterprises and people are storing data in more places, new categories of
backup data recovery have emerged. These include:
 Granular recovery of files, folders and objects – also known as file-level or object-
level recovery, this is the process of quickly getting back one or just a few specific
data sets from among many volumes.
 Instant mass restore – this process allows it staff to recover not just files but
hundreds of virtual machines (vms) instantly, at scale, to any point in time, saving
time and resources.
 Volume recovery – a process teams that need to recover an unlimited number of
vms at the same time used for faster recovery; for example, all vms belonging to
an application group.
 Virtual machine disk (vmdk) recovery – this recovery process ensures all data and
apps on a vm are restored quickly.
 Bare machine recovery – restoring an entire operating system (software, apps,
and data) in one process.
 Instant volume mounts – teams can save time using a backup solution as a target
to restore an entire volume to a windows vm.
 Instant restores of vms – this process restores a large number of vms to any
previous recovery point with backup copies fully hydrated and available
immediately.
THE INTERNET
The internet, sometimes simply called the net, is a worldwide system of
interconnected computer networks and electric devices that communicate with each
other using an established set of protocols. Today, the internet is a public, cooperate
and self sustaining facility accessible to hundred and million of people worldwide. It's
used by many as the primary source of information consumption and has fueled
the creation and growth of its own social ecosystem through social media and
content sharing. In addition, e-commerce, or online shopping, has become one of
the largest uses of the internet. Millions of users shop for and sell products on the
internet using popular e-commerce and marketing platforms, such as amazon and
shopify.
How the internet works
The process of transferring information over the internet from one device to
another relies on packet switching. The internet is a packet-routing network that
uses ip and tcp protocols for communication. When a person visits a website, their
computer or mobile device sends a request to the server over one of these
protocols.
Difference between the world wide web and the internet
The key difference between the internet and the world wide web (www or web) is
that the internet is a global connection of networks, while the web is a collection
of information or websites that can be accessed using the internet. In other
words, the internet is the infrastructure and the web is a service on top of it.

The web is the most widely used part of the internet. Its outstanding feature is
hypertext, a method of instantly cross-referencing text. Used in blog posts,
hypertext markup language (html) web pages, social media posts and online
shopping websites, hypertext appears in a different color than the rest of the text
and is often also underlined. When a user clicks on one of these words or phrases,
they're transferred to the related site or webpage. Buttons, images or portions of
images are also used as hyperlinks.

The web provides access to billions of pages of information. Web browsing is done
through a web browser, such as chrome, edge or firefox. The appearance of a
particular website can vary slightly, depending on the browser used. Newer
versions of a particular browser can render more complex features, such as
animation, virtual reality, sound and music files.
What are the key features of the internet?
The internet has certain features that make it a powerful and versatile tool for
communication, information sharing and diverse online activities. Some key
features of the internet include the following:

 Worldwide availability. The internet is a global resource that's accessible

to everyone. Today, most people can use the internet even if they live in the
most remote and deserted parts of the world.
 Compatibility with other media types. Due to the standardized protocols
and formats that it offers, the internet facilitates compatibility with various
media types. This enables seamless integration and interaction across
diverse multimedia such as photos, videos and audio files.
 Easy accessibility. Web browsers such as chrome or firefox are used to
access the internet. For end users and developers, these programs are
simple to use, comprehend and easy to develop.
 Affordability. The expenses associated with developing and maintaining
internet services are low. However, the costs vary depending on the type of
services and providers being used.
Uses of the internet
In general, the internet can be used to communicate across large or small
distances, share information from any place in the world, and access information
or answers to almost any question in moments.

Some specific examples of how the internet is used include the following:

 Social media and content sharing.

 Email and other forms of communication, such as internet relay chat,
internet telephony, instant messaging and video conferencing.
 Education and self-improvement through access to online degree programs,
courses and workshops.
 Searching for jobs -- both employers and applicants use the internet to post
open positions, apply for jobs and recruit individuals found on social
networking sites such as linkedin.
 Entertainment such as streaming tv shows, movies, videos and music.
 Remote working using online collaboration platforms and messaging apps.