Windows 7 - Problem with full screen in games

I installed Windows 7 Ultimate build 7.6 on my laptop (GeForce G102M,2.2 GhZ T6600), and when I tried playing games (Unreal Tournament 3,America's Army,Gunz) which worked perfectly on the same laptop with Windows Vista, the games don't desplay on full screen. The screen is like trimmed from the sides and I'm playing on half the screen,I downloaded the lateset video drivers (for Windows 7 of course) and checked the resolution settings, there's nothing wrong there.
What can I do to play games on full screen?

Set the game's resolution to be one with the same aspect ratio of the screen.

How come I didn't do it when I had Vista and it worked perferctly?
Can it have something with the fact that I installed Directx11?

Because Vista is WDDM 1.0 drivers not doing the right thing and stretching the screen by distortion.

Win 7 = WDDM 1.1 driver working correctly.

You didn't install DirectX11. It is natively part of Windows 7 install.

What's WDDM?
I downloaded DX11 from microsoft.com and installed it....

Windows Display Driver Model

I ran into a problem:
Highest resolution in the game is 1024 by 768, but when I set my screen resolution to that the screen gets "trimmed" on the sides and I only have half my screen (I can see the entire screen but it's smaller than it should be).
To show you what I'm talking about, I took a picture of my screen after I changed the resolution to 1024 by 768, it's not the best quality but its enough so you can understand.
Click here!

I know what you mean. If that really is the highest res available in the game, there's nothing you can do.

You need to use the correct aspect ratio to avoid the black areas, when gaming.

Actually I just found a solution... "Flat screen scaling" was set to "use my desplays built-in settings", and I changed it to "use Nvidia scaling" and now I run the highest res there is and games adjust on there own....
Thanks for your help!

Yes, but the screen is now distorted, making a square appear as a rectangle.

You're welcome.