%APPDATA% is as simple as home but much better on the clutter front.

True. I actually kinda like the Windows directory structure since Vista. If only the application devs would also follow the standard (hence the whole My Documents mess).

Incidentally, Emacs will use %UserProfile%\.emacs.d if you set %HOME% to %UserProfile%, which, as a UNIX user, I personally prefer for consistency. While not Emacs-specific, another trick I've found useful is that, on 64-bit Windows, you can open %SystemRoot%\System32\somefile in 32-bit Emacs iff you refer to it as %SystemRoot%\sysnative\somefile (the original path yields %SystemRoot%\SysWOW64\somefile).

It didn't use to work. I think it was added for XP SP2 or so, probably due to the popularity of manu *nix ports like Emacs.

It always did, at least in NTFS.

What did not, and still does not, is to create them via Windows Explorer.

You can create them just fine from the command line, or via Windows APIs.

You can create them in Windows Explorer with a little trick: type the name with a trailing dot. Entering ".vimrc." will save as ".vimrc", no trailing dot.

Great! I was not aware of it.