If you have the original Star Wars Knights Of The Old Republic 1 (KOTOR 1),look for the mss32.dll file in the main directory.Copy and replace it with the mss32.dll file in your
KOTOR 2 directory.And make sure to have the game in Windows XP SP2 compablity before you run it.
It worked fine for me,using this solution.
And make sure you have a backup copy of the original mss32.dll file in the KOTOR 2 Directory