Neverwinter Nights 2 freezing?

Neverwinter Nights 2 freezes after I meet Khelgar. I've tried making a new character and it still does it. I have an Asus G73JH-X3, so my specs are definitely good enough to run the game. I'm running Windows 7 64 bt. I've tried running it in compatibility mode, with administrator privileges, changing the processor affinity so it only uses one core. I bought Neverwinter Nights 2 Platinum on Steam. I tried verifying the files, they were fine and there was no change. Does anyone have any idea what might be going on an how I might fix it?