You people might want to search on the viruses you've gotten, Ive seen some before that you can't get rid of by just hitting a button (as in no, norton can't get rid of it). You have to go into safe mode, delete registry keys, edit files and so on. It could just be that you think you've gotten rid of the virus, when you really didn't. Especially now with the rootkits some of these things have come up with :: , you can't get rid of them easily at all. They manage to hide files so well that you don't even know they are there.