pc games through hd tv

so i connected my pc to my hd tv using the hdmi cable- mygraphics card is an radeon HD 5770 so it can support hd displays yet anytime i try to play any game on mytv i can only play them on in very small windows any time i make them fullscreen the screen goes blank and unresponsive
any ideas?
Answer #1
The resolution you’re using may be out of the range of the HDTV.