I am running a GeForce GTX 460 graphics card, to play videos on my htpc. As of a couple of days ago, I can no longer make adjustments to the video parameters using the card. I have tried all my players (PowerDVD11, VLC, and mpchc, using both dvds and blu rays). It had been working perfectly until two days ago. I have dropped down every menu I can see with no luck. Re booted the pc, etc. I can still adjust the desktop, and I can still change resolution on the graphics card output, but no video adjustment. Any ideas?