Sorry you have to go through all this , a usb drive would not be my choice of a backup , it can get infected, you should only use a CD. You have to be real careful what you back up. A few months ago another poster had this virus and on his first post he said he could not figure out what was going on as he had reformated and reinstalled windows FOUR times and he was still infected, something he backed up and reinstalled just kept infecting him.
You can post here in our Windows Forum for help if you need it. I can link to it and make them aware of whats going on.