how to get rid of spanish in menuing

We have a roomate who speaks spanish, so she installed MSN instant messenger in spanish on our computer. It changed all the menus and everything to spanish. She is not too familiar with computers, so we have no idea how it happened, as does she. She only intended to have that particular program operate in spanish, but I don’t see how that is possible. We uninstalled the program, and it removed most of the spanish, but some of it remains in bits and pieces here and there. Some menus remain in spanish, as well as the blurb at the bottom of windows explorer, which says “Mi PC”. We had a friend who operates a help desk at Nortel look at it, and he couldn’t figure it out. A 2nd computer guy friend couldn’t either. What are they missing? Don’t want to reinstall windows.

Thanks