well then that is the actual problem because Battlefield 1942 requires 800 by 600
to be supported by the display monitor.
a workaround would be to connect your laptop to a TV which supports that resolution or a monitor
Am I able to change the display in the game itself, so I can use my laptop monitor or would I have to plug in a new monitor each time?
I'm afraid that won't help because the main menu still requires 800 by 600 despite the hd fix that is included in the gamespy patch which actually allows the game to run in full HD or 4K resolution. the main menu will still stay in 800 by 600.
by the way the hd fix made fhsw look gorgeous in 4k
https://www.youtube.com/watch?v=bpDMLK05G1Y
