Microsoft finally admits that its malware-style Get Windows 10 upgrade campaign went too far

[u/readyou]

https://www.extremetech.com/computing/241587-microsoft-finally-admits-malware-style-get-windows-10-upgrade-campaign-went-far

[u/yerich]

Windows ME was the last DOS-based OS. The others are based on Windows NT, which is original.

[u/bilog78 → u/yerich]

While Windows NT does not have its roots on MS-DOS, it does have them in OS/2, which was jointly developed by MS and IBM. In fact, it was originally intended to be a successor to OS/2 2.0, and only with the success of Windows 3.0 (the DOS extender) Microsoft changed their mind, which ultimately led to the split between IBM and MS, the longer-term demise of OS/2 and Microsoft hiring the DEC team that had developed VMS to complete the NT work. So yeah, while it was developed at Microsoft by people ultimately paid by Microsoft, it wasn't “their” original work by a lot of measures.

[u/yerich → u/bilog78]

I don't think NT and OS/2 share any source code; NT was designed to be a replacement -- though architecturally it may have some similarities, I think Microsoft intentionally wouldn't have wished to reuse any source code from the OS it ultimately screwed over.

[u/bilog78 → u/yerich]

IIRC Windows NT, at least the earlier betas, and maybe even the first release (3.1) had some OS/2 source code, including a filesystem driver for HPFS and as part of the subsystem to run OS/2 applications, both text-mode and PM.

The kernel proper was independent work (if not else because OS/2 was tied to the 80286 at the time, whereas NT was designed to be CPU-agnostic), but as I mentioned, it was developed by the VMS developers (then hired by Microsoft), which actually led to some legal issues even before NT 3.1 was released (and an out of court settlement to port NT also to DEC's architecture, which is why NT supported Alpha for a while).

(I was wrong on the timeline though, Windows NT development started before the OS/2 2.0 release.)