A computer virus is a program or set of programs or set of program or set of programs that can cause damage to computer system. It may disturb the normal working of a computer system. The code in computer virus is attached to some part of operating system or computer programs. The instructions in the code tell the computer to perform some task. This task is often destructive such as:
- A computer virus can damage data or software on the computer.
- It can delete some or all files on the computer sytem.
- It can destroy all data by formatting hard drive.
- It may simply display a large happy face on the screen.
- Some viruses only slow down the computer and cause no serious damage.
A computer virus is passed from computer to computer. A virus can be attached to any file that is copied to computer system. The user may download files from Internet or copy programs on floppy disks that may contain viruses. These are the most common ways of getting a virus on computer system. Many virus are speed through emails. Generally, a user cannot get virus by simply reading an email. However, certain virus are very dangerous such as Klez. These viruses are automatically spread when the user opens the email. The virus is spread even if the user does not open the email attachment. Normally, a virus is activated when the user executes a program that contains virus. For example, a user may have downloaded a computer game from Internet that contains a virus. The virus will be activated when the user runs game on the computer.
Antivirus
Antivirus is a software that is user to detect and remove a virus on computer system. A virus can be stopped from entering the computer with the help of good antivirus program. The antivirus software checks all files to detect virus. It can be installed and configured to work in the background. The antivirus program should be used carefully. It should match with the operating system. For example, a Mac computer should use an antivirus program that is specially written for this system. Similarly, a computer with windows operating system should use an antivirus program that is specially written for Windows. A mismatched antivirus program may cause unstable behavior and may crash the computer system. New viruses are written everyday. The antivirus companies constantly update their antivirus programs to protect users from new viruses. Most popular antivirus companies are as follows:
- McAfee
- Symantec
- Panda Software
Some important benefits of using antivirus programs are as follows:
- Antivirus program protects important data from virus.
- It checks all files before they enter computer system.
- It alerts the user about the virus before it causes any damage to computer.
- It quarantines or eliminates a virus so that it may not harm computer.