interesting - so:

If you buy xp home you may install it on your own personal computers *I have 4 comps*?

BUT if I want to help a buddy out by re-formatting his system - even though he HAS XP home already on his system... I have to buy a new copy to do that ?

I'm just curious about how Microsoft does this wacky licensing business because I have four comuters myself - one cheap old Dell for word processing and net surfing, one old crappy Dell for music, one old latitude laptop for taking to class and word processing, and my new rig that i build this summer for living on.

EDIT: sorry spoke before reading the above post... you can only use XP home on one computer unless you get a volume license?