It's gotten more interesting in Windows 10. With a hi-res surface, scaling often plonks screens in confusing and arbitrary places when docking/undocking. My method is now something like "Alt+Space, M, Hold Left for a few seconds, Hold Up for a few seconds, Hold right for twice as long as Left, Hold Down for twice as long as Up, etc". And it won't work at all on Java sub-windows, who just scale and move any which way. And hitting Win-Left or Win-Right may not even snap the window to a viewport, meaning the secret button nor the red X are at a window extreme.

It's certainly added a fun little extra layer of puzzle to my life. I bet this is how Catherine felt about Atrus' door puzzle locks as she wandered Myst Island.

Seriously? Undock leaves windows offscreen? Well, 10 < 95, I guess.

I do alt+space, m, left arrow and then move my mouse - window jumps to the mouse. Some arcane stuff to recover your window...

Win+left/right arrow also works for this since Windows 7

Not for subwindows, like dialog boxes that take focus on a program.