I found a tool called “WinaeroThemeSwitcher” for Win7 and 8.

http://winaero.com/comment.php?comment.news.209

TS switches to your various themes without a GUI getting inbetween. Works from the cmd line, if you point it at a theme in one of the known paths.

Or you can set up a shortcut with a target similar to this:

C:\themeswitcher “C:\Users\usernamehere\AppData\Local\Microsoft\Windows\Themes\mycustom.theme”

^^ I have a few such on the desktop. They work nicely, because like I said, there’s no Personalization window coming up first.

Because of Aero Theme Switcher, I can now dump a bunch of rickety unreliable autohotkey scripts I’d been using for this job.

The only thing I’d call a drawback, is minor. For the current theme, there will be an “Unsaved theme” created as well. It’s probably needed, for reasons that I don’t know.

ETA: This program also works on Windows 10. I tested on the Fall Creators version. So far, no downsides. If anyone else wants to see if there are any bugs, the program is linked above.

Hope you like.

—Moon