Black Bars on each side of screen

Ok, so whenever i play a game, not just maplestory, and it goes into the fullscreen mode, i get these two black bars around my screen. This only started happening when i updated to windows 7. When i was on windows vista, the game took up the entire screen. Does anybody know how to fix this? I think its some kind of setting with the graphics card that i need to fix, but im not sure how. Here is a picture of what im seeing to clear it up:



Any ideas as to how i fix this?
I have an ATI Radeon HD 3200 graphics card if that makes a difference
Thanks in advance