I had trouble getting NWN to work as well, although this problem extended to WinXP which caused me to get a new mobo. Might want to check out hardware as well. It's the bright one, it's the right one, it's Pratell.
I had trouble installing, but I am beginning to think it was my CD-ROM. I copied the entire game to my desktop and installed from there just fine. I'd recommend trying that for you problem as well. Bronus Blackblade
Order of the Shining Path