OK so here is the problem I connected my gaming PC to a big screen TV and when I but it back with my old monitor I could only get a corner of the screen and I could not change the settings. I then put the computer back on the TV and changed to a smaller resolution. Now I don't get a picture from either of the displays and I do not get error codes. I can get my PC to work with a different agp card but I still can't change the settings for my main card. Here are my specs. MSI motherboard Pentium 4 one gig of ram an nvidia geforce 6800xt AGP and a Antec neo HE 380watt PSU. Also the nvidia tech support has been pretty unhelpful.

Try re-installing your main video card. After you re-install the drivers, go into the video card's properties, & setup profiles, one for your PC & one for your Bigscreen TV(especially if it is HD) You should be able to move back & forth between them saved profiles without any problems, that's what I did with my 8800GTX

Pcfixinman