An antivirus program works by identifying and removing virus and other malware from the computer. Here are some of the methods used:

Signature based detection This is the oldest and most common method of identifying virus and is used by all programs. The antivirus software has a data base of known viruses and malware against which every new file is compared. Viruses attach themselves to every file, so not only is the file analyzed as a whole; it is also analyzed in part by part.

Detection of suspicious activity The anti virus program keeps on working at analyzing how the computer and various programs are working. If it finds that something is not working properly or that a program is not behaving in an accepted way, it investigates the program. This system works for unknown and new viruses.

Analysis and Emulation of Files Some files contain programs that may be viruses. If some program or file has certain instructions that may harm your hardware or data, these files are analyzed by the program. The files may be even executed in a protected way to carry out quarantine and repair actions. This may slow down the computer quite a bit.

Once the virus is detected, the antivirus program sets about to do three things:

1. It quarantines the file, making it inaccessible and neutralizing the threat.

2. The antivirus tries to repair the file. Since a virus embeds itself into files, the antivirus tries to remove the viral code. However, this is not a 100% successful operation since the file may have got damaged.

3. The antivirus deletes the file if the file is totally damaged.

All quality anti virus programs are equipped with an inbuilt virus removal tool that takes the above steps to remove the virus from your computer.

Most antivirus programs come with built in options that can be keyed in to schedule virus checks on your computer. They start the scan, which can be set to run weekly or twice a week or even once a month. They scan your computer, isolate and quarantine malicious files and delete them if you so desire, protecting your system. These programs are continuously updated for new virus definitions and they keep your system protected against the latest threats.

New viruses keep on being created and the above methods give sufficient protection against viruses which have been listed as well as those that have not yet been identified. All quality anti virus programs follow these steps to protect your computer and data from virus and other related malware.

Viruses are getting increasingly sophisticated. There was a time when they were written by amateur pranksters. Now they are written by professionals with criminal intent. These work silently, do not exhibit exhibitionistic pop ups and can cripple systems all over the world. It is in your interest to protect your system and data by installing a good and reputed anti virus program which updates itself daily and scans your computer regularly.