I have an AMD Radeon HD 6900 on my new rig I got for Christmas. For some reason it refuses to let me play games in full screen mode. When I try, it seems to put the system into hibernation after a few minutes of play. I have checked and it does not appear to be an overheating issue. I can play the most recent games in full screen window with no problem. My major gripe is that since I like to play some older games, many of them do not have a windowed option. I would very much appreciate some help.