[coretx]

- 3.x was just a GUI for MS-DOS.

- 95/98 are a OS on their own although still having quite some old DOS code in there.

All others versions are following the NT tree.

NT 4.0 for non-x86 hardware deserves a honorable mention despite the fact i'm absolutely not a Microsoft fan. It was quite impressive during it's time, but hardly to be seen anywhere.