If you have access to a clean machine, you should consider installing Kaspersky AV (you can get a 30 day functional demo from their website), and install PE Builder. With this you can make a bootable rescue CD that you can boot into on your infected machine, and run the virus scan without having your boot drive online or your compromised OS running.
Of course, it's possible that critical windows components are badly infected, and just because an AV removes them it doesn't necessarily give you back a fully functioning windows install.