called as w32.USBWorm
No offense but you are assuming that not only is this the worm\virus that is on his system,but that it is the only one.... and that the "System Volume Information" is not hiding anything either and is clean. AFAIK @Nikhil has already tried solutions that should have worked for the worm you are mentioning. IMO it is best to be sure that these little pests are completely gone, I have had problems with these types of worms before, and they are very stubborn and usually come in multiples... not singles