Is it possible to switch to pmode even with EMM386 running (ie while in virtual 86 mode)? No it's not, right? Then how did Windows do it...?

The thing is, EMM386 is microsoft code, so obviously they can call functions to do whatever they want.

There is some function discussed somewhere that discusses which int will allow you to do this. I forget where I saw this though. I can't think why there would be a need for it though.

Thank you, neonz!

So that works under EMM386, but not in a DOS Prompt under Win 3.1 or 9x, right?

dunno, you can also try VCPI - http://www.nondot.org/sabre/os/files/ProtectedMode/VCPI.txt

A DOS box should only allow DPMI access to pmode, anything else would be too dangerous in the context of a protected mode operating system.