Do-it-yourself: How to clean an infected computer
Is your computer infected? Here’s a link on basic information about viruses and a few lists of tips and resources here
There are various free solutions that may help you remove a virus from your computer and get it back up and running. It is a nuisance to have an infected computer. The virus may be hiding from the scanner. You can sometimes fix this by booting into Safe Mode, but newer viruses are even smart enough for this trick. Sometimes, booting into a known good operating system and scanning from there is the only way to go. There are a number of free anti-virus Live CD's available from the Internet. Just burn it to a CD and reboot. It is always good to have a couple of these sitting around for just this purpose. A list is provided on the IAS Network Security website under Malware > Antivirus Live CD.
A complete set of instructions on how to clean an infected computer can be found on the ITG website.