Here’s a guide on how to play Metro Exodus in windowed mode.
Metro Exodus is an incredible game, but it has its flaws. A big flaw is that there is no option in the settings to change the game to borderless fullscreen or windowed mode.
First step: Create user.cfg
If you have not already started the game and saved a game state, do it to create the user.cfg file. If you have already played the game, skip to the second step.
Second step: Find user.cfg
It’s either in one of these locations: C:\users\your name\metro exodus\1236173686(some number) OR C:\users\your name\Saved Games\metro exodus\some number
Third step: Edit user.cfg
Open the user.cfg file and scroll down until you find r_fullscreen on, change it to r_fullscreen off.
The second thing you need to change is: r_res_hor and r_res_vert. Just enter there your desired resolution.
Now save and close the file and start your game. You will see that borderless window works now.