The basic idea for any platform is:
- Open a Command Prompt / Terminal.
- Change to your ioquake3 directory using
cd C:\Programs (x86)\ioquake3
- Then run
ioq3ded.x86_64.exe +set dedicated 2 +set fs_game cpma +map q3dm17
+set dedicated 2 part if you don’t want it listed on the master server.
I’ve added running on Windows to the Sys Admin Guide.