My game crashes when I open it in fullscreen - DarklightGames/DarkestHour GitHub Wiki

Step 1. Navigate to Red Orchestra directory.

By default, Red Orchestra is installed to: C:\Program Files (x86)\Steam\steamapps\common\Red Orchestra.

Step 2. Find DarkestHour.ini

Once you're in RO directory, navigate to DarkestHour/System and open DarkestHour.ini.

Step 3. Locate the StartupFullscreen line and set it to True

With DarkestHour.ini open in notepad (or your editor of choice), hit Ctrl-F and search for StartupFullscreen= line. There will be multiple matches: you want the one under [WinDrv.WindowsClient] category.

When you find it, replace the value after = sign from False to True. The resulting line should look like this:

StartupFullscreen=True