On all Windows operating systems I have used, this workaround (winkey+left/right) unfortunately does not work for moving modal pop-ups.
For example, when starting KeePass by opening a .kdbx password safe file, KeePass will first open the master password input modal pop-up.
If that happens on a turned-off screen (IMHO it opens on the screen on which the KeePass main window was placed before the process exited on the previous run), you'll be lost.
Very frustrating, e.g. for multi-screen home theater setups.
Anyone please share your solutions to this problem.