To me an OS has to be able to Install and Run without the help of another OS. Windows 1.0-3.11 needed DOS. Windows 95,98 and ME still needed DOS.

The older windows were just pretty dos extensions and mainly just add-ons.

DOS is a real OS, and NT/200/XP/Longhorn/Blackcomb are real OS, but WIndows 1.0 2.0 3.0 3.1 and maybe 3.5 weren't real OS's, on this note an Operating system allows you use of you HW, DOS does this bout work with the CPU directly as well as your BIOA and vieo card, all windows did wassend the commands to DOS, and eventually MS made those command windwos based, but if DOS is still present, that Windwos isn't a real OS it's dependant on DOS.

A bit off topic: Today I visited one good old man, who runs a hardware store in the city. I got (from him) two useful, interesting books:

*Microsoft MS-DOS - User's Guide and User's Reference (Operating System version 4.0) 430 pages (!)
*Microsoft MS-DOS - Shell User's Guide and User's Reference (Version 1.0) 118 pages

cool.... MS-DOS 4.0... and the manual really states "Operating System version 4.0". Add-ons to my personal museum

One of Twelve anytime you want some museum items I have them come take them away. MS DOS 1.0 - 622 I will never use. I have hardware too.

I'd love to come & take them away. I build these museum computers at times. I've got, for example, two laptops, one Sharp PC-5500 with MS-DOS 6.22 & Windows 3.00a - another Olivetti Echos P90 with Windows NT 3.51 (SP5, new shell)... one P75 runs now with Memphis (98 beta 3, build 1629).... I've got lots of museum hardware too, and a couple of 386's in pieces, and I don't know if my wife wants them to increase. But Operating Systems, yes please, I collect them, but I live so far away..

I agree your OS definition - it has to run without other OS, so, I call DOS' an OS, but 9X just an extension.

Pocket Linux is cool

2k and XP are REAL OS's ...NEt is even more of an OS

I have used all the Windows Family Products except Windows 1.0 or whatever it was the one before 3.1.

What is the most change from the Windows OS?
My Opinion is the Windows 3.1 to 95! When 95 came out I was shocked and I was happy to try it out and use it. It was a BIG Improvement from 3.1 and then came XP from 2000 that was a BIG Improvement also but not like 3.1 to 95. It was fun to try 95 for the first time I was kinda like what is this at first when i tried 95 but i tried out the new features and well again like i said it is a big improvement.

Food for thought:

An operating system serves as an interface to both hardware and software. True that Windows 3.1 and 9X were just a pretty glove covering DOS, it still was a shortcut method to interface with hardware and software.