It's probably even older, I dunno if that thing overwrites for any new updates or service packs but summer 2004 was about the time SP2 was realased so August slides right in there. But yeah, people who format and reinstall every month are crazy, I'd have to go through all that crap and reinstall all the drives and reset everything, then again I don't use windows updates but even then you can easily just update your old image in 20 minutes anyways....
It is unusual that everyone seems to have a 2007 install date though, you should only have to reinstall about once a year at the most I would think