All of a sudden the gl_gamma command does not work for me anymore. QW starts up very dark and stays that way no matter what.
Everything was OK until yesterday when this happened. I haven't changed any video settings or installed any software lately.

There is unlikely it is any setting in QW itself causing it because I tested starting ezquake-gl.exe up with default settings (no cfg at all) and it is just as dark as my own cfg.
I now also uninstalled the nVidia drivers and installed the latest version - no change.
I have tried changing resolutions and different video settings followed by vid_restart, including vid_hwgammacontrol and vid_forcerestoregamma.

It's a GeForce 8800 GTS running on Win XP, latest ezQuake version.

There is especially two things that somehow might have an impact on the problem, but its a longshoot:
*) I have radmin server installed, but not started as default. I recall starting up QW once with radmin server running and QW was as dark as it is now. (When all was well)
*) I use Camtasia Studio with Directrec Configuration tool always running as a tray icon

I'm also aware of that it can be a hardware problem on the GPU (GeForce) - but if something is broken then bigger problems should arise and not only the gamma problem? I'm quite lost.

Any help appreciated,

Have you played around with any VNC type program?

*Edit - I see that you mention radmin, check to see if you have some extra display driver installed, I've experienced the exact same thing with VNC display drivers in the past.

Yes i have two gpu drivers (in Device Manager):
NVIDIA GeForce 8800 GTS
Radmin Mirror Driver V3

What now? And should I check for other types of VNC software, you mean?

Edit:

I disabled the radmin driver and..voila! it worked. I can change the gamma command again.
However, now another problem arose. It feels very laggy, as if the monitor hz is back at 60, or worse (Even though On Screen Display shows 800x600 @ 75 hz)...

How to solve ?

Sorry, I don't know - didn't experience that, only the part about gamma not working with mirror or hook drivers

it's solved now
thanks for helping Zalon
altough I don't know why i have to disable the radmin driver (needs reboot every time) when it worked before..

just uninstall it, it's not needed for radmin to function, it's just to give better performance