Computer Basic Training

Computer Fundamentals

Dos-Disk Operating System

Windows - 98

Windows - Xp


Computer Basic



HTML - hyper text transfer protocol

File Transfer Protocol

Computer Virus






Computer Glossary



What is a computer Virus ?

Computer virus is a program that is loaded onto your computer without your knowledge and runs against your wishes, They perform some activities like deleting files or disturbing your computer settings. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.

How Computer Virus Affect Your Files ?

Computer virus affect mostly, .exe, .sys, .bin, .pif etc Virus can affect any files on your computer . Virus have the capability of infecting any file; however it will generally infect executable files or data files, such as word or excel documents which are opened frequently and allow the virus to try infecting other files more often.

Properties of virus
Computer virus generally increase the size of the file, however more sophisticated viruses changes can be hidden .
It can delete files as the file is run. Because most files are loaded into memory, once the program is in memory the virus can delete the file used to execute the virus.
It can corrupt files randomly. Some destructive viruses are not designed to destroy random data but instead randomly delete or corrupt files.
It can cause write protect errors when executing .exe files from a write protected disk. Viruses may need to write themselves to files which are executed; because of this, if a diskette is write protected, you may receive a write protection error.
It can convert .exe files to .com files. Viruses may use a separate file to run the program and rename the original file to another extension so the exe is run before the com.
It can reboot the computer when executed. Numerous computer viruses have been designed to cause a computer to reboot, freeze, or perform other tasks not normally exhibited by the computer.

Different Tools To Protect Your System From Virus :

Spy Ware

This won't damage your PC in anyway, Spy ware runs on your computer and logs what you do, where you go, it looks for patterns in your behaviour and logs it. It will then send this information to a server, where people with use this info to target specific audiences. Spy Ware comes in many forms, sometimes embedded in a program, as separate files, and sometimes through webpages. You are most likely to pick up spy ware with free software as part of the installation.


These programs open up your computer to other users over the net, it allows them to perform various tasks, such as take over your mouse, open programs, delete files and such. They are dangerous, as they usually shut down virus scanners, trojan removers and firewalls themselves.To protect your system from trojans, use a firewall, and trojan remover

How Viruses Are Contracted

In the past the majority of computer viruses were contracted from users sharing data using floppy diskettes. However, with the increased popularity of the Internet most computer viruses are contracted today through e-mail and by downloading software over the Internet or P2P sharing.

Note: Never open an email attachment from someone you donít know. Avoid opening an e-mail attachment from someone you know , unless you know exactly what the attachment is. The sender may be unaware that it contains a virus.

Our Featured Links :


Copyright © 2006 Computer Services. All rights reserved.