unable to find display mode with OpenGL acceleratio

When i want to start some games i get this error:

unable to find display mode with OpenGL acceleration.
Make sure you install proper drivers for your video card as recommended
in documentation and set your desktop to 16 bit (65536 colors).
Please see ReadMe file for troubleshooting information.

i dont know why, first the games worked normally, but now they broke…

i use:
windows XP SP1
DirectX 9.0c
XFX Geforce 6600 GT

i already reinstalled my XFX driver, but they dont have something like a OpenGL driver of something…

what to do?

Either the driver is not installed properly or the games have issues. Did you try GLinfo?
http://www.delphi3d.net/hardware/index.php

Ok, i did that, heres the report:

http://www.gamerzplanet.net/upload/userfiles/ronsijm/GLInfo.htm

Looks good.
You could try running other games like Quake2, Quake3, half-life, NeverWinternights, MDK2, medal of honor, Jedi knights, etc.