[Nino Marino]

ATI video cards have a feature built in to their drivers called “Theater Mode” which I think does exactly what you want – it will automatically play any video to a secondary monitor in full screen. This feature should let you use any media player you want. Fortunately you’re still running XP as, in Vista, the feature only works with video players that use the overlay renderer due to DRM restrictions. Nvidia used to have a similar feature but it looks like they’ve removed it from newer drivers, probably due to the limitations in Vista.

Hope this helps!

–Nino