How do you mean dull?
Resolution has nothing to do with brightness which is what you're implying.
If you right click on the Win 7 desktop and click screen resolution what resolution does it say?
Do you have any other options when you right click. I have a GTX 670 and mine says Nvidia Control Panel and I can change settings on that.
Lastly, can you change anything on your monitor?
And as RealBeast says, what graphics card do you have?