In Windows - It’s also possible to run X under Cygwin. But it’s a bit of a pain to set up and get working properly.
And by extension - it is possible to get Gnome, Cinnamon, Mate and even KDE working. I’ve also had 2wm, dwm and xmonad running on top of X11 in Windows.
BUT - it cannot replace the Windows desktop.
AFAIK - it’s not possible to replace the windows desktop at all. If you’re running Windows, you are limited to the Windows desktop environment.
But you can run X, with a different desktop, as a Windows application, in Windows.
And if you don't believe me - here's a screenshot from my Windows 7 work PC, running X11 with dwm. The image is very large, so zoom in if you need to!
I've loaded up speccy and pressed the windows key, to show the menu - so you can see this IS windows and NOT Linux with a Windows theme.
At work, I use cygwin a lot. Because Windows built in cmd and Powershell terminals are awful and incomplete. Cygwin provides a much more complete set of tools in one place.
I haven't been downgraded to Windows 10 at work yet, so I haven't tried WSL yet. But I suspect I'll probably just fall back to cygwin if it doesn't meet my needs.
Whenever I need to use more than one dwm session at a time - I will fire up X/dwm and then open up a several terminals and attach them to different tmux sessions and then use dwm to manage the different applications I have open.
dwm has been my choice of window manager/desktop on all of my Linux PC's for many years. And surprisingly, it's extremely useful in Windows at work too!
I've experimented with various other desktops on Windows, but most of them are very quirky/buggy when running under Windows. dwm works flawlessly though!