in our office we spec them with XP Pro. Any that come with Vista get wiped and rebuilt pronto. We are hoping to bypass Vista completely and go directly to the next (hopefully bettre) OS. Heck, we probably still have 100 computers running Win2k. We are trying to get all of them upgraded. Oh and our MACs give us no end of trouble. We bought 5 IMACs in one month and 4 had to go back to Apple for parts/rebuild. One went several times.