It does get frustrating with crashing and all...
I own a 6600GT in a nForce2 board AGP version.
It's my other gaming unit in my living room.
It took me a bit to get that running strong, but now it's solid.
Prey, Quake4, HL2, Fear, all run nice...
I took the fan off the video card and reset it with silver paste to shave off a few degrees for gaming.
-Make sure the power connectors are tight.
-Use the CD Rom connector for power connector sharing
-Avoid using HDD plug, it needs isolated power to it.
-Card is snug in port
-Check Ram timings, too tight? Snug in board?
-Run dual channel RAM if available, verify with CPU-Z
-Update nVidia chipset platform drivers.
-CPU Cooler snug and functional.
-If AGP, disable fast writes in BIOS
-Adjust AGP aperature to 256 mb
-Update sound card drivers too, (it too can crash a game)
Windows SP2 needs to be there and all other updates to stabilize.
I would suggest updating the mainboard chipset drivers as well as video.
Then remove old video driver in Add/Remove in control panel.
Reboot and reinstall with latest nVidia video drivers.
Reboot again and configure settings, i.e., display/refresh etc.
Realize that gaming is like racing, everything is almost full throttle.
A small rule of thumb is that is you crash to the desktop, video is starved or errored.
A total crash, reboot, CPU is starved or overheated as well as software error or RAM error. Also make sure your 12V rail has 18 amps and above.
All this can result in "no fun gaming" machine.
So in a nutshell, check the hardware, Bios etc., then start on XP software to configure after making hardware adjustments.
After re-doing all that run a benchmark to see if OK. Run DX diagnostic in XP to see if any errors, you can find it from System Information menu.
Run direct X test 7,8,9 to see if running OK.
Reboot, then try you game.
It ought to be better now.
Hope this helps,
Del ;-)
Dual Opteron 850's
nForce4 Pro
2 7800GT's in SLI
Raid 0 500 gig
XP Pro SP2