i run win 7 pro 64 bit.
its a great mixture of xp with the better points of vista tossed in (yes i know there isn't very many good vista area's )
it runs very stable very few bsod...and i mean very few.
all in all it is the best release from microcrap to date..
warning though...unlike older versions of windows this one does not like hardware changes that require fresh o.s installs.
microsoft is doing this to try to hinder multiple computer installs of the same key.
i think they have failed because of the huge population of hacked, non-legit copy's of this program out there.