Windows Media Player 12 full screen problem

Hi everyone! I'm using Windows Media Player 12, but in full screen mode (Alt + Enter), the frames are not full screen, they are limited by the Play bar (I login as admin).
When I login as a different user, the full screen mode works normally, the frames fill up my screen. These are 2 photos of 2 logins. I guess I changed some options but I can't find out.
Hope someone here can help me! Thank you very much!

@Wishmaster: Thank you for your reply! I tried it but nothing changed! The frames are still not full screen! Have you got another idea?

@kado897: Thank you so much! I checked some options but I didn't notice it! Now it's OK. Thank you so much again! :)