have you gone into the settings on the pc and activated the DVI port on the back of the pc to output a signal? sometimes this needs to be activated manually to actually work.


Right click on the desktop, go to the nvidia control panel and on the tabs click something to do with mutiple screens?

you may have the option of clone or dual view, dependign on config an ddriver version.

also make sure your screen resolutiuon is not set higher than your TV can handle.

HTH