Left4dead2 stutters intermitantly no matter what I do. problem never happened till I trried getting newer drivers. Installed win7 3 times so far and the same thing happens. I've taken out and reinstalled the vid cards...no change. Ran the vid cards one at atime and together...no change. Did the same with the ram sticks...no change. Is this a HHD issue or am I looking at a mobo change out....oooooooorr more windows corruption? Please help.