The best guaranteed way to get rid of a virus is a full format and OS reinstall.
Sorry, it's probably not what you wanted to hear, but a lot of virus pave the way for other viruses. You'll find that you might get rid of it, but you'll have more problems shortly after. Bite the bullet and do a full format reinstall.
(Obviously, backup important data to something first, and be very careful that you don't carry the virus with you in the backup).
If you really don't want to do that, check out HijackThis. It might help you figure out where the virus is attaching to the system.
[Disclaimer: HijackThis is an advanced tool that lists potential attachment points, not detected viruses. do not just blindly clean everything that HijackThis detected. HijackThis should be used to analyse the state of your computer, it is not an automatic clean up tool. If you are at all unsure, post your HijackThis log report to a security/spyware/virus forum (Not here, there are dedicated forums for this) and get an experts advice before taking any action)]