GF6600 black screen problem

I just built a new computer:

Asrock 939DUAL-SATA2 motherboard
Athlon 64 3200+
1024 MB DDR400 RAM
ASUS N6600 256MB (Geforce 6600)
480W Antec PSU

Everything seems to work fine except one thing...
In Call of Duty 2 (after the intro movies which work fine) the main menu is just a black screen but the music is playing and I can select options at the menu. Serious Sam 2 starts at a black scren as well. In Civilization 4, at the main menu the background (A spinning earth globe) works fine but the small window with buttons in it is invisible (I can still press the buttons with my mouse as if the window still was there). Doom 3, however, works perfectly fine.

I have the latest nVidia drivers installed.

Anybody knows whats wrong?

I guess it was some problem with DirectX, as Doom 3 is OpenGL and it worked. Anyways, I solved the problem by reinstalling Windows.