You have to have another drive that already has an operating system installed. The easiest way to do this is (if it's an IDE drive) to set the jumpers on the back of the drives to cable select. It should have an instruction sticker, or something to help you with that. Once that's done, just plug the infected drive into the end of the cable, and the master drive (the clean one) into the center plug. I'm pretty sure that the middle plug is master device... anyone's free to correct me if I'm wrong. Then you just boot from the master drive, scan for viruses, and remove them. If the viruses persist, then copy all but the infected files over to the master drive, and reformat the old drive. Problem should be solved. However...you'd have to have an extra drive sitting about. I believe it would have to be the same file system (or operating system to make it easier) anyway. Hmm.....yeah, unless the files on the drive are irreplaceable, I'd just format and start over...