ok man. heres the deal. to be able to run the gimp's interface it has to use a program called GTK+ (which converts the linux api to windows interface api or something like that)
go to this page. now download the thing called "GTK+ 1.3.0" from one of the four mirrors. install it.
go back to the same page and look for the next part which says "GIMP 1.2.4" and download it from one of the mirrors. install it. have fun. more probs just note me or something