The only way to test this is either remove the graphic card and test it (not practical) or use a live linux to see if same issue. the other way is to install windows 7 as dual boot just for a while to test it .could always delete that partition and remove the boot entry from windows manager. otherwise can't keep guessing. and yes a virus is most likely too . download sophos virus remover(free) and see. your specs are top can't complain