could be windows 8, and i don't believe current drivers are fully supportive of windows 8. But hang in there. NVIDIA recently announced that Microsoft has begun certifying NVIDIA Geforce drivers alreayd for windows 8
make sure on your older games in windows 8 your running them as an administrator. if not the game cant update itself or run right. also if it wont run in windows 8 try running it in xp service pack mode 3.