None of the ALT Tab solutions are working for me. When I run the batch file, I get:
File C:\Windows\AppPatch\Custom\{3565ae7a-df66-4901-94fd-50821b5ffb9b}.sdb is not installed. Uninstalling Halted.
twice, and then Press any key to continue.... which closes the window and does nothing else.

I tried using DXWND.exe as well, but while that will launch a windowed version of the game, either significant portions of the game are not rendered in the window (IE it is merely the top left quadrant of the game) or the whole window is rendered, with a black box extending roughly 30% past the borders of the game itself. In this case, it is not possible to click on any of the menus without extra effort, as the button positions correspond to random areas in the black space beyond the game graphics, but still within the window.

I am far more surprised when ALT TAB works properly than all the numerous games and programs where it does not work properly!

Usually when i press ALT TAB, my expectation is that nothing happens at all and the program remains open and unaffected...... windows 10 on 2 different laptops and a desktop computer.