Windows 3.x could (and defaulted to where possible) to running in "386 enhanced" mode which actually used protected mode, IIRC. The problem was that the Win16

Windows 3.x could (and defaulted to where possible) to running in "386 enhanced" mode which actually used protected mode, IIRC. The problem was that the Win16 part ran all in one address space, and the separation support was mainly used to handle DOS windows.