INTRODUCTION TO COMPUTERS 2

SOFTWARE

Software is any set of instructions that tells the computer

what to do. It is what guides the computer and tells it how

to accomplish each task.

A program is a sequence of instructions written to solve a

particular problem.

There are two types of software

1.System Software

2.Application Software.

System Software

The system software is collection of programs designed to

operate,control, and extend the processing capabilities of

the computer itself. System software are generally

prepared by computer manufactures. These software

products comprise of programs written in low-level

languages which interact with the hardware at

a very basic level. System software serves as the interface

between hardware and the end users. Eg. Operating

System(OS).

Operating System Software

An operating system (OS) is a set of programs that manages

all the activities among computer hardware devices.

Types of operating systems

There are three main categories of operating systems namely

•Stand-alone Eg. Disk operating systems (DOS),Windows

OS,Linux, Microsoft, Mac OS X.

•Network Eg. NetWare, Windows server 2003.

•Embedded operating systems Eg. Windows Mobile 2003,

Palm OS, and Symbian OS.

Application Software

It allows end users to accomplish one or more specific

tasks.

Typical applications include business

software, educational software, medical software,

databases, and computer games.

Forms of Application software

Application software can be in one of the following

forms:

•Packaged Software: is software that is produced and

sold to meet the needs of different users. Example: Word

processing and Spreadsheet

•Custom software: it is designed to perform specific

functions for a business or industry.

•Shareware: is copyrighted software that is distributed

free for a trial period.

•Freeware: is software that is provided at no cost to a

user by an individual or company. It is also copyrighted.  

• Public-domain software: it is also free software, which

has been donated for public use without any copyright

restrictions. Anyone can copy and distribute public

domain software to others.

TURNING ON THE COMPUTER

Before you switch on the computer 

•Check the cables which are connected to the system

unit.

•Check the main socket connection

•Remove all removable storage devices, if any, from

the system unit.

STARTING THE COMPUTER 

Booting is the process of starting or

restarting a computer. There are two

types of booting.

1.Cold booting refers to the first time

the computer is turned on after it has

been turned off completely.

2.Warm booting refers to when the

computer is already on and for one

reason or the other has to be restarted

(re-boot). Restarting a computer can be

done in each of the following ways:

•Pressing the (CTR+ALT+DEL) keys

together and choosing restart from the

task manager.

•Selecting the restart button, from the

turn off computer dialog box

•Pressing the reset button on the system unit.

TURNING OFF THE COMPUTER

Use  the shut down procedure of the operating system, to

turn off the computer. so that various processes are closed in

sequence, and items in memory released properly.

Why should you turn off the computer?

• Help save energy                                                               

•Keep the computer more secure                                                                 

•Help start the computer quickly the next time to use    

NB•When adding or upgrading the hardware inside thecomputer such as: installing memory, a disk drive, a soundcard etc. disconnect it from its power source beforeproceeding with the upgrade.When adding a printer, monitor, and other hardwaredevices that do not connect to the universal serial bus(USB) port on the computer shut down before connectingto the device.

Shutting Down the Computer

PC Shut Down Options

In earlier versions, windows uses standby mode to save the

users work to memory and puts the computer into a power

saving state without turning it off.

Hibernate

It’s also used to save the user’s work on the hard disk and put

computer into a power saving state.

Sleep mode

In modern versions of windows it combines standby and

hibernate into a single power saving state called sleep. When

the computer is put in this mode,windows automatically

saves your work, turns off the display, and any noise from

the computer’s fan stops. To wake up the computer, press the

power button on the computer and enter your password (if required).