High School Antics

I work as tech support for Littleton Public Schools. A student or two at one of our high schools has figured out how to rename the “Start” menu. Rather than “Start” it now says “Poopie”. So far we have just re-imaged those machines since they are primarily student machines, but I would like to know how they do that. So far Google and Microsoft KB articles have not been any help that I can find.