i recently started playing KotOR and it was running smoothly, then, it started not actualling seeing my razer naga as a mouse, so i bought a cheap basic mouse. Then it would show the first two loading screens (lucasarts and BW corporation) then went black and showed my desktop; When this happened it showed up on the windows bar but when pressing Alt+tab or windows+tab wasnt showing up. ended up having to go to task manager and shutting it down. so, the only way i can get it work is just restarting my PC everytime it does that until it works. this was going fine for me until i had to leave the 3rd PLANET i had been to, no matter where i went it never LOADED fully (always a tiny slither not loaded), and then resorted back to the desktop problem. To fix this i have looked at other people's problems on the web and all of the ways to do it that i haven't tried are after a re-install.
The problem with this is when i press un-install/change in the CONTROL Panel it comes up with

"C:\progra~2\common~1\instal~1\engine\6\intel3~1\ctor.dll\uninstall_cmd".

 now i have looked that up and the BEST thing people have is to re-install windows, im hoping someone can help me with this because i do not want to re-install everything ive got on here.

Any help would be great


Edit: im running Windows 7 Ultimate if that HELPS