Computer virus is a dangerous and frustrating technology of the computer world. It harms the computer in many ways depending on its intensity as computer viruses are in many forms. They are actually (man-made) pieces of executable code that execute them selves when ever the infected programs are being executed. Computer viruses are like a disease that may cause a computer to be completely damaged. It replicates itself once it enters into a network, personal computer, laptops and then it may attack many programs of the system.

Computer viruses attack the files and other important data of the system without the permission of the owner and even without his knowledge it may destroy the whole system if it attacks the hard disk or the operating system. It may reformat the hard disk. It also sends bulk emails or virus infected emails to the email addresses in our address books.

It enters the system through CDs, DVDs, Flash memory and mainly from Internet when we download some files or receive infected e-mails etc.

HOW TO DETECT IF THE SYSTEM IS INFECTED:
Viruses usually slows down the efficiency of your computer, when you feel your system is slower than before , run anti virus to scan your complete system. The small viruses damage the clock of the system even if you set the clock regularly it again gets wrong. The folder view of the system also gets infected, i.e.-e the hidden folders are not visible even if you check the option of show hidden files. The viruses slow down the system also, so keep an eye on these defects to know about virus infection.

HOW TO BE SECURED:
• Install an updated version of any good anti virus in your system, without that you will be unable to secure your system form infected items.
• Always scan the emails, other attachments and files that you download from Internet because once they enter your system then they replicates them selves and may infect your whole system.
• Be careful while accepting any sort of files during chatting etc
• Create back ups of your important data and keep in disks away from your computer.
• Always use new diskettes and if some one else have used them already then scan them first.