What's the lowest resolution you can set your monitor to
because Battlefield 1942 in the beginning needs a monitor that support 800 by 600.
if that's good make sure the Microsoft game DVR is off.
now it's time to check what version of Battlefield 1942 you have.
there are two versions cd rom or origin download you can check if you have that.
Your game will be installed in the following path.
C:\Program Files (x86)\Origin Games if you see a folder named battlefield 1942
you got the origin version
in that case you only need to patch up the master server.
with this patch http://team-simple.org/download/battlefield_1942_gamespy_patch_v1.61.exe
However if your game is installed in the following path.
C:\Program Files (x86)\EA GAMES if you see a folder named battlefield 1942
you got the cd rom version.
https://docs.google.com/uc?id=0B7cGjW31oHh8eEFHdG1JNzhLeUU&export=download
you need to fully patch up your game.
if battlefield 1942 still doesn't work after all this then you're against the hard to find problem.
make sure you don't have any screen overlay programs installed,
like overwolf for teamspeak or any overlay programs that are turn on by your graphical driver
turn all off if that still doesn't work out
me and my mates are always ready to help on discord fhsw community
https://discord.gg/2zVSCk2
or TeamSpeak
https://www.gametracker.com/server_info/5.9.54.21:9987/