For those not old enogh, a little history lesson...
Windows 3.0 Yes
Windows 3.1 No
Windows 3.11 Yes
Windows 95 No
Windows 95 SP1 Yes
Windows 98 No
Windows 98 ME Yes
Windows 2000 No
Windows XP Yes
Windows Vista NO
Windows 7 Yes
Windows 8 ------ See a pattern yet?
For those that don't remember, 3.0 3.1 and 3.11 were more than point updates, they changed the way Windows worked, added networking as standard and introduced a lot of the concepts that we take for granted today. But they got it wrong in 3.1 by making networking an addon extra!!
Win 95 was a big step change from Win 3.x and it didn't work, until the release of sp1 when it mostly did.
Win 98 undid a lot of the changes to Win 95 and Win 98 ME (Millenium Edition) became the one to use untill Win Xp (The less said about Win 2000 the better)
Vista continued the alternating sequence of break it / fix it, with Win 7 being everything that Vista could/should have been...
So... Win 8 is next and true to form... it is mostly un-usable in business.
Win 9 should be really good though!!