I know you're probably thinking I could just disable the monitor but that won't work.

Basically I have an HDMI cable going to my amp just for high-def surround sound (as SP/DIF can't do high-def). Unfortunately the HDMI standard requires that there's a video signal to go with it. If I disable the display then I get no sound.

So I have a third monitor which is sent to the amp but I never want to look at or use. Unfortunately windows sometimes decide to go to that window, which is a pain.

Is there any way to prevent windows going to this display?

By the way I can't just mirror another display onto it because my other displays have different resolutions, which my amp doesn't support.