avast! Virus Cleaner is a free tool that will completely remove selected viruses & worms from your computer.  
It is able to stop viruses that are active in memory, it will disinfect your files, remove virus registry & startup items, and even delete the virus working files.  
Currently, it can handle the following virus families: Badtrans, Blaster, BugBear, Ganda, Klez/Elkern, Nimda, Opas, Sircam, Sobig, Yaha, all including the latest variants.