I hate resurrecting old tickets, but in an effort to up the activity in here... Actually, this ticket could do with an answer anyway.

I'll make a single assumption, and this is that the poster was attempting to watch a DVD on their television.

Okay, so having connected your television via the appropriate video cables you will set your graphics card to output as either Clone (to see the same image on both screens) or Span (to split the image across the two screens). My personal preference is to use span - this is simply as I can have a film/game playing full screen on one side, whilst keeping the other screen for other functions.

The important thing is that video from a DVD will only be visible on the primary screen (part of the protection system). This means that when you have Media Player (or any other DVD playback software) on one of the screens you will see the film, on the other screen you will just see a black screen.

Simply change the primary screen in your display settings in order to play the DVD on your television screen. You will of course want to ensure you set the other screen as primary before disconnecting everything. Also, if like me you use the span option - remember to turn it off unless both screens are set up to run with the computer permanently - otherwise when you come back you will find that programs opened on the other screen will still be over there.

The other thing to remember is that the resolution your TV can cope with will depend upon its type. For instance, my Mitsubishi (CRT) television could happily cope with me setting it to 1280x1024 - however, everything looked much better at 1024x768. LCD screens are built with a 'native' resolution and running outside of this, generally degrades the image noticably. Projection screens require you to be careful as it is very easy to induce screen burn on these with still images.

Of course, with many modern Hi-Def screens these days you can simply plug in and treat it like a monitor (although the definition is never as good for the money).