Question about NT Version Number

[fexuaz555]

Also, what you mentioned for Whistler (Windows XP/Server 2003, obviously) was undoubtedly due to the fact that the version number 5.1 was almost certainly the plan from the beginning, but that it didn't actually shift from 5.01 (which seems to be an anagram of 5.1) to 5.1 until later as far as the hardcoded kernel was concerned. I don't personally think that Microsoft actually changed any plans at all during Whistler's development, but that it was simply a matter of changing the version number that is embedded into the kernel.

whistler/xp is 5.01, not 5.1. Just most things got recoded to say 5.1 rather than 5.01. However some things still exist that output 5.01..

Just like server 2003 is really 5.02, win7 is really 6.01, 8 is really 6.02...

I thought that 'NT 5.1', XP Version number equals 'NT 5.10' before seeing above post.
After seeing it, I have the confusion. I'm still confused about NT Version Number like 5.1, 5.2, 6.0, etc.
Does NT 5.1 equal NT 5.10, or NT 5.01, not NT 5.10?

[Roo_the_Vickty]

MS played at that time
XP was at first 5.0, then 5.01, then 5.1 which is 5.10
server 03', was 5.1, and then 5.2

Longhorn/Vista was 6.0, tho at some build 6.05

[Courage]

Until the Windows XP branding was mostly finalized (first build to actually use it in most places is 2465), all Whistler builds showed the build number in the System Properties dialog box. In the builds that have the NT version number as 5.1 (first leaked build to have it is 2223), the build string shows '5.01.2223', not '5.1.2223' as in all other places. You can draw your own conclusions from this point.

BTW, Longhorn itself never used 6.05. That version number was reserved for its IE versions (like 5.60 for early Whistler builds).

[Battler]

Actually, 5.01 and 5.1 are one and the same in this case. What happened during XP development was that Microsoft changed its version numbering system. In the old system, 5.1 was the same as 5.10 as version numbers worked like decimal numbers, while in the new system, 5.1 was the same as the old system's 5.01, while the old system's 5.1 became unambiguously 5.10. Windows XP was simply the old system's 5.01 and the new system's 5.1, binary 0x05 0x01. The earliest 5.1 builds probably displayed 5.01 because the OS itself still used the old system to read version numbers, but as they switched all parts to use the new system, it began displaying 5.1.

[os2fan2]

One might note that Windows NT 5.x has a DOS version style hack, where you set instances of 5.1 or 5.2 to get the thing to run under 5.0.

The exact format is 05 00 00 00 01 00 00 00 and 05 00 00 00 02 00 00 00. Taking these as little-end 32-bit numbers, this gives 05 01 and 05 02. The string exists in the likes of schtasks and task(list/kill). Changing these to 05 00 00 00, 00 00 00 00 makes the utilities run under Windows 2000.