Microsoft → Re: What's to come of Vista?

You remember incorrectly.

There were two lines of descent:

1) Classic DOS-based Windows:

Windows 1.0 to 3.11, Windows for Workroups 3.11, Windows 95, Windows 98, Windows ME.

2) New Technology WIndows:

Windows NT 3.1 to 4.0, Windows 2000.

In 2002, the 'upgrade' path for both lines of descent was Windows XP. Microsoft never pushed 2000 as an upgrade for ME. ME in fact only exists because Windows 2000 was seen as too scary for existing DOS-Windows users (they had to add all the simplifications you see in XP Home to make it palatable).

What is your criteria for establishing DOS based versus non-DOS based ? I'm sure you are well aware that XP and Vista both employ a Disk Operating System as did all previous versions of Windows. My definition of dos based Windows would be anything older than Windows 95. Windows 3.11 you could close that last "Window", and have the DOS prompt blinking at you. That was not an operating system so much as it was a GUI file manager. That was "DOS" based. Win 95 and up were not that way.

They are a disk operating system (because they're disk-based and they are an operating system) but they sure as hell ain't DOS.

My criterion is quite symple: if the hardware boots code that is largely identical with the product formerly known as MS-DOS, then the OS is DOS-based. Based on that reason, Windows up through WfWg 3.11 was obviously DOS-based (DOS was a prerequisite product), and Win 95/98/Me were DOS-based because the DOS code became part of the "Windows" product, but it was still DOS, and except for ME, you could directly boot into it by choosing the approriate startup option.

On the other hand, the Windows NT line of descent is clearly not DOS-based. One piece of evidence for this is (a) DOS was written in Intel x86 assembler, (b) the first machines running NT were MIPS R3000-based workstations which don't execute Intel machine code. x86 support came later.

XP and Vista are descendents of Windows NT. The only DOS code that's there in XP and Vista is (a) the DOS emulation that's in the program NTVDM.EXE, and (b) the DOS files that sit around waiting to be copied when you format a bootable floppy.

I have considerable kernel programming experience in both the Win9x family and the WinNT family. I can assure you that, in kernel mode, it is clearly obvious whether or not DOS is present. Hence this posting comes from a position of sure knowledge.