If you’re having problems making the game full screen in Fallout 4, you can fix this problem by adding a few lines of code to the game’s ini file.
To do this:
- Close Fallout 4 if its open.
- Go to your system disk.
- Navigate to Users > Your Windows Username > Documents > My Games > Fallout 4 folder.
- There must be a file named “prefs.ini“. Open it.
Add following lines to prefs.ini file:
save the file and exit.
This should fix your full screen problem in Fallout 4. Open the game to test it.