Because Arma uses a lot of keys for every action I regularly encounter the following problem:

When the game is set to Borderless Fullscreen, when you press ALT+ENTER it changes to Windowed mode.
A workaround is using the Powertoys to disable the keypress entirely (not working all the time).

Can you either disable the ALT+ENTER option entirely (or ignore it for switching to Windowed mode)?