Everything not starting with ''#'' is your current setting.
So right now you're using: 800 x 600. I changed mine to 2560 x 1440, change yours to match your aspect ratio or raw resolution.
Edit: if that doesn't work either, you can try going to the ''properties'' of the .EXE file of the game, then go to compatibilty settings and change the DPI scaling to "System (enhanced)"