Is it possible to run multiple instances of Windows Explorer within a single user session, or configure multiple desktops that are portions of a screen?

I don't know the best way to describe what I want to achieve, but here's a picture of what I've got:

I've got a 4 monitor setup, 3 portrait and one landscape, and I am normally running a number of RDP sessions, outlook, chrome, a development environment or two, so on and so forth. Most of these applications support full-screen views which mostly or completely hide the window borders, but on the Windows Desktop they take up a full monitor to do so.

What I want to do is have 7 "desktops", "regions", call them what you will, each of which is, for the purposes of applications running in it, a "full screen" environment:

I'm not tied to Windows Explorer for this, in case it helps - a different window manager that will support this functionality would be a perfectly acceptable answer.