stuck safe mode resolution

Everytime I install Vista my screen resolution is stuck at 640x480 and it does not allow me to change it, I've installed all the drivers possible and upgrading the current ones to fix it. But it will not give me any option other then 640 x 480. When I upgraded to Media Center it did the same thing but it cleared up once i installed the drivers. Why isn't Vista? Need Help soon.

Everytime I install Vista, My screen resolution is stuck at 640 x 480, it does not give me any other options. I have installed and updated all possible drivers to fix it, but it stays the same. When i upgraded my computer to media center it did the same thing, but it cleared up once I installed the Drivers. Why doesn't Vista? can anyone help.