It's WIN.COM, by the way.

When Windows didn't have a driver for some hardware, it would tell you it's "using 16-bit driver" (or was it DOS driver?). So it's all 32-bit.

Hah, this reminds me of Win32s on Windows 3.1x...

Yes, WIN.COM was the file. All I can remember about Win32s is that it added another level of DLL hell.