Secondary Full Screen Maximizes to Primary

Hey, I have a problem with my new setup, but it's not a new dual monitor setup, as I've had this for a while with the old 6600gt. After resintalling windows, putting in a new video card and loading up with Omega drivers, I can't remember/find the settings to allow the secondary mode to display fullscreen. Like for instance, I play a movie in Window's media player and click full screen, it will take over the primary desktop. How do I fix this? Thanks.