...make sure to rub your feet good - N - hard on some thick carpet before opening up that tower!!!
....ok, I'm a punk @ heart!!...
..sounds about right, I'd check the BIOS setting first. I don't think the repair-man would've opened up his tower to rid him of the 'virus'...unless he planned on washing the Motherboard with alcohol to kill those germs.
..what da heck do I know!!