Greetings Cuse! Welcome to the PCHF
I actually used to have a similar problem. I used to believe it was power supply related, as I was running about 5 watts over the limit of my power supply...whoops
Unfortunatly, as you're not getting any error messages, it's not going to be the same solution
First thing to try is to update your drivers (as Blue has already touched on).
You've got an nForce4 board, which you should be able to get WHQL or modified drivers from here (
nVIDIA Geforce 7900 7800 7600 7300 6600 6800 GT GTX ATi Radeon x850 x1900 x1800 1600 1300 XT Pro - Guru of 3D: PC Hardware Reviews) and you'll also be able to pick up video card drivers.
2nd thing you want to check, is temperatures. Right click on your desktop, select Properties -> Settings -> Advanced -> GeForce 6600 GT -> Temperature Settings
This will let you know how hot your card is running...if it's over 60degC...then you've got ap roblem with this, and you should clean out your case of all dust (DO NOT USE A VACCUUM CLEANER!).
If you've tried all this previously, let me know
