We have some expensive pitney bowes mailing systems. We inquired about a newer computer, NOT running xp. Turns out they changed the entire print assembly for the version that runs Windows 7. Its a $20k upgrade. (also need a new controller box, old one doesn't work with WIndows 7 software (mainly the hardware dongle, apparently)..
Our brand new pitney bowes mailing system has a windows 7 computer. The techs that installed it told our senior management to never run windows update, or install antivirus on it, or it would cause problems and make the machine not work. Boy did they get pissy when I put it on its own vlan, with only access to one server, and one port on that server, to get its updated files.