I recently bought both games, since I really enjoy pretty much anything related to Star Wars. I did play both games some time ago, but never completed either.
While KOTOR 1 works fine, without any adjustments/patches, however, TSL has an on/off relationship with my computer. A little while ago, the game worked, even on Win7, but now it doesn't anymore.
While all these fixes worked for those earlier cases, they don't now. Whatever fix I try, it won't start. In the Task Manager, the process "swkotor2.exe" runs but there's no CPU usage. Also, the amount of memory used ranges from approx. 10,000 - 40,000 kB after the secuRom check, depending on the compatibility mode.
The game only starts when I disable sounds, suggesting it has something to do with that (probably Mss32.dll), but I've tried all fixes I could find. Even using the .dll from the first game didn't help. Running the game unpatched or with 1.0a didn't work either (I have the EU version).