That tool is Easy2Boot, and don't let the janky UI put you off because you will want to learn what it can do. My only ...
Xbox Ally handheld owners, if you're not loving Xbox Full Screen Experience, you can stop it from booting at startup. Better yet, here's how to replace it with your preferred game launcher.
Time to flip open those Microsoft Windows history books, because this might be one of the only mentions of "OS/2" on this ...