2. Computer Security: Anti Virus

A computer virus is a software program that is designed to copy itself over and over again and to attach itself to other programs.

Viruses do not damage the computer hardware. They affect the data and programs stored on the computer.

They can cause an immense amount of time wasting and financial loss for people and businesses. For example, the "Melissa" virus was so effective in spreading itself that many huge corporations had to shut down their email systems until the virus could be contained.

The operating system tries to make sure that data is not corrupted by viruses. In order to do this, anti virus software is used.

There are a number of anti-virus programs available for wiping out  viruses for example Norton, McAfee, Sophos and AVG.

The anti-virus software contains a database of known viruses. Every time a file is opened, the anti-virus utility checks the content, looking for hidden viruses against its database.

When the utility recognises a virus pattern, it will alert the user, and ask them whether they want to remove the virus and clean the system, or whether they simply want to 'quarantine' the virus.

New and more damaging viruses are being written all the time and so to keep up with these new threats, the anti-virus companies provide constant updates to their software. Normally, you log on to the internet and the software will update itself either automatically or after a certain period set by you.

There is usually a small annual fee involved for this service, but it is a small price to pay for peace of mind.