Windows classic style is there but not loading

I once believed that my windows classic style was missing because when I saw the XP styles it had a folder and the classic style didn't; plus the file was like 3kb and I couldn't believe that classic style could be that small until I searched for it on another XP running computer that had a working classic style. But I do have the classic style file but it just won't load. I was wondering if anyone else had this problem and was able to fix it or if anyone has any suggestions. The error message iI get when I try to use it is that "the file failed to load ". I would also apreciate anyone telling me of any downloadable theme programs that have a similar sleak and simple style just in case my attempts at this are futile. Thank you in advance for any help.