I have an EVGA GeForce GTX 560. I finally got off the phone with someone at the big box store in tech support. He advised me that they have had SEVERAL people around 40 on his watch in the last 2 weeks come in for this problem, and it seems to be a problem with the HORRIBLE windows 8. I was advised to call 800-microsoft to walk you through fixing the problem. This is supposed to be done with least amount of resistance by the service team if you do this within the first 90 days of purchase of your computer/windows 8. I will update if I have success tomorrow.