do you know my parents?? im not evan alowed to post on fourms enless there waching or the teachers arent
No, I am sorry, I did not mean any offence by the way. What I am trying to tell you though, is that that what is being recommended to you ('turning off' a core for that specific application) is optimising the performance of your computer, without resorting to any risk or out of the ordinary, to be honest, user conduct. It's no more detrimentary to your computer as it is upgrading say your drivers or virus defintions.
In any case, good luck, it's one hell of a game!
Dual-core processors work fine with KotOR with no tweaking at all (at least with an XPS 700). And in my experience restricting a program to a single processor on a dual-core system has never changed anything.