Screen resolution problem

I have a ASUS VG248QE Black 24" 144Hz 1ms every time I try to play Forza 4 i get black bars at the top and bottom of the screen about an inch and i try’ed changing the aspect but it dose not work how can i fix this?

Is your aspect ratio set to 16:9 in your Xbox settings? That is a 16:9 monitor, so it should fit the screen perfectly if you’re on an HD resolution with that aspect ratio.