I just recently bought KOTOR on steam and it crashes at the main menu I'm having no luck finding a fix on the Lucas Arts forums i was wondering has anyone else encountered this problem and found a fix 
I'm running Windows 7 Ultimate 64-bit  

Hm, try creating a desktop shortcut, then have it run in compatibility mode.  I don't think I had a problem with the game on Vista 32-bit. 
 
Edit:  It appears other users have been having problems with this game as well.

iv tried that running with compatibility mode and having it set to administrative rights i thought installing the patch would help but it makes the game unplayable as it says at the start you need the disk even though its a digital download ah well thats 8 euro down the drain  

if anyone else is having this problem I found the solution to the problem what you must do is go to  
control panel -> system -> advance -> data and performance and then add then add the .exe on to the DEP list  

I had a similar problem on vista (it would actually play, but freeze & stop after playing for 5 minutes). I tried a few things to fix it, but I think the one that worked was program that disabled one of my processor cores (on my dual core processor) and it ran fine. Apparently KOTOR doesn't like multi-core processors, & disabling the additional cores helps. 
 
I can't remember the exact program I used (sorry I couldn't be more help) but hopefully a google search should be able to find it.
 
EDIT: Just read the replies in more detail and have seen you actually fixed it. Obviously wasn't the same problem I had then.

DEP sucks!