I've got Intel GFX, but I can't find such options in the Intel GFX panel.
Printable View
Well that could be your issue, why don't you have your VGA drivers installed in first place?
Check your PC specifications to find out the name of your graphic card, google it + latest drivers, install them and afterwards try to change resolutions for the black bars.
you do realize that noone actually plays with black bars?
People just add the black bars to a video with editing software --'
Look in your graphic card software that comes with it.
https://i.gyazo.com/fcde8a3eb5dc5f02...6bdf01f164.png
and enable GPU Scaling.
Its not stupid, 4:3 scale is a lot better than 16:9 also 16:10, and the characters looks bigger so u can aim easily.