Almost all games from Winxp will be able to run on Win7 even 64bit, you just have to run it on compatibility mode. Knights of the old republic 1 and 2 runs on Win 7 even on 64bit.
How did you get KOTOR II to run? I installed it and it would basically crash when I attempt to start a new game. After doing some research I found a lot of complaints that KOTOR I & II does not run in Vista or Win 7.