@ jeremy's transparency
No, MS can count, but they've been running two streams:
Personal: Win 3, Win 95, 95 OSR2 (=96), 98, 98 2nd ed (=99), ME (=2000, cos they couldn't merge it with NT like they thought, but had already handed over the year number)
Network: NT3, NT4, Win 2000 (= NT5), XP or 2002 (=NT6), Windows 7 hooray in 2010 (=NT7)
I remember when Win 95 was launched, the advertising told us we'd never need another Windows OS because they'd issue patches forever hahahahahahahahahahaha