What is the WORST a virus could do to your computer?

[brisray]

A virus cannot harm the hardware. There was a virus called CIH or Chernobyl that took advantage of a combination of Windows 95, 98 or Me and a particular type of chip. This virus did a lot of damage to some of these computers as it was able to overwrite the BIOS firmware to the extent that some of the infected computers BIOS chips had to be replaced - but that was back in 1998. I suppose a virus may cause the processor to do so much work it could try and overheat it - but nearly all computers have thermal cutouts and will turn themselves off before the CPU is damaged. I suppose a virus could be written to move the hard drive heads so rapidly that they become damaged but I've not heard of any of either type of viruses.

For the things the worst computer viruses can do see http://www.catalogs.com/info/travel-vaca...ruses.html

Viruses can hide in all sorts of computer files and it's easy to name an exe file to anything you want. For example - your_worst_nightmare.exe can easily be renamed something_nice_for_you.exe.
You may also find something like this lovely_song.mp3 .exe

Malware can infext all sorts of files, Word documents (in scripts), audio and image files - but those a pretty rare.

As for a good anti-virus program then any mainline program will offer good protection and everyone has their favorite. I like Microsoft Security Essentials - http://www.microsoft.com/security_essentials/ which is free.