Merging multiple user interfaces

I have windows XP Pro. I had it at home 1) before I had
xp, 2) at school on the domain/networked aspect of XP,
and now 3) at home in the home interace.

I therfore have 3 identities on the computer, all with
their separate my documents, preferences, IE favorites,
etc.

I would like to merge them somehow without having to move
all of these files. I don't remember the preferences I
had, and the computer i know is the one I had networked
for 4 yrs. How do I recover all of that without having to
go out and in of "documents and settings" ? Thanks