Yes, basically the only "Windows" that was actually a full blown OS was Windows NT. The Win 3.x stuff was running on top of DOS, 3.11 ran over 6.22 which oddly was incompatible with 3.1 and 6.2 (I had the latter versions of Windows and DOS). Basically DOS and Win3.x had some patchwork to run 32-bit stuff, but the OS was still DOS. It extended as well into Win9x, but DOS 7.0 was hidden away from most users' eyes so few non-tech people noticed it. It also had everything pancaked with Win9x layered over Win3.x layered over DOS. You could even see which layer blew up by looking at the error windows/messages:
- Win9x style window: Win9x layer.
- Win3.x style window: Usually a GPF or some GDI error. It meant the error comes from the 3.x layer.
- BSOD: You hit something really low level, probably on the DOS layer. The whole screen was in text-only, DOS format.
The jump in Win2000 and WinXP to the NT kernel did wonders for Windows.