[mamelukesabre]

3.1=1
95=2
98=3
me=4
xp=5
vista-6

[Poser]

NT 2000 was the one I used the longest. I’m still running a server with that operating system. It works great. Eight SCSI drives in two Raid configurations with a Dell Server with two power supplies. Good stuff!

[Revolting cat!]

APOLOGIST!

[Neanderthal]

3.1=1
95=2
98=3
me=4
xp=5
vista-6

WIN 2000? Did ME come out at the same time?

[Last Dakotan]

What about my favorite Win2K?

[Sparticus]

3.1=1
95=2
98=3
me=4
xp=5
vista-6

Not exactly :) There was the old pre-win95 OSes 1 through 3.x

Following those the official numbering series is:

Windows NT 3.5 = NT 3.5
Windows NT 4 = NT 4
Windows 2000 = NT 5
Windows XP/Server 2003 = NT 5.2
Windows Vista/Server 2008 = NT 6
Windows 7/Server 2008 R2 = NT 6.1


Windows 8 should probably be 6.2 as the kernel is an evolution of the NT 6 one.

[Disambiguator]

Windows actually split into two distinct families for a while when the original NT version came out. There were the consumer versions (3.1/95/98/ME) and the industrial versions (NT 3.1/3.5/4.0/2000). Windows XP uses the NT kernel, whether the home or pro version, so it was basically where the two product groups converged again.

All Windows desktops now use the same OS kernel (NT), and now it’s all moving to 64 bit from 32 bit.

[ShadowAce]

You forgot Win 2000 and NT