well, we really can't help you until we have a lot more information about your friend.
first, we need his/her computer specs. all we need is the proccessor, video card, sound card, and how much memory the computer has. kotor comes with a system checking tool that is fairly useful in helping you figure out problem areas. you can access it by selecting the "Configuration" option on the autorun menu (the window that opens up when you put in the CD). in the window that opens up, select "Scan Hardware" button at the lower left of the window. then, that will give you all kinds of info on the machine you're using.
second, driver info on the video and sound cards helps a lot, especially with ATI video cards.
third, game settings, specifically graphics settings.
anyway, if you can think of other kinds of helpful info, then by all means, post it.