I've had NWN installed on my vista rig for some time now but never got it to work. Had finished it when still on w2k and installed it so I could still play user made modules or persistent worlds.
Every few months I mess with getting it started and fail until today!
Tried the stuff here: bioware forum - compatibility mode stuff
but it didnt work.
Today stumbled across GOG forum mentioning to just rename nwmain to something else. Renamed it to nwmain1.exe and now it runs
Only other tweak was unselecting 'Enrironment Mapping on Creatures' or everyone was invisible (using AMD card not sure if for everyone).