Personally, I'd back up all my files and format the hard-drive, and re-install everything nice and clean. Its kinda a PITA, but not really that hard. Just make sure you back-up everything first, or else it's gone for good.
Some programs will allow you to re-install them over the original, re-writing some of the corrupted files, or replacing lost ones. Sounds like this virus progam is deleting/changing them, so not sure that would help much.
Erik
