Windows 7 Problem with Windows Media Center and Games

[Megus17]

I'm not sure why it is doing this but when I try to start Windows Media Center I can't access the screen. I try switching between screens and can see that the program is running but I can't use it. Also when I am playing a game and try to switch between the game and desktop with alt + tab or win + tab it kind of freezes and changes the resolution of the game screen to default. If anyone can help me fix this problem I would greatly appreciate it.