I get a lot of crashes too, where it makes my whole computer shut down. After doing a lot of investigating, the most likely culprit is a program that nVidia uses called "Powermizer," which tries to throttle the amount of power your video card uses based on the usage of your PC. The problem is that it's really buggy and is especially buggy with OpenGL, which NWN uses. I just found the below fix on YouTube. I haven't tried it yet, but I will and I'll let you know if it solves my issues.
The author's notes before starting:
- Have set the Power Management from 'Adaptive' to 'Maximum Performance'
- Have Clean Installed Drivers (removed all previous Nvidia Display Drivers and Installed Fresh ones)
- That your graphics card is NOT damaged or overclocked too high
This requires you to mess with your registry, so before to make a back up prior to attempting what is seen in this video.
[youtube=560,315]http://www.youtube.com/watch?v=Zt00C-HXFbA[/youtube]
The link the guy is talking about to the software is broken, unfortunately