Full-screen resolution screwed up

[Swaffy]

My laptop's screen resolution is 1600x900. So it's wider than the game screen if it was scaled up to fir my screen.
So when I play BF1942 in full-screen mode, it should be scaled up to fit my screen, and I should end up with some black space to the left and right of the game screen.

I forgot what I did to make this happen, but BF1942 is now being stretched to the full screen of my laptop, no black space on the sides, which makes the game stretched wide.

How can I fix this? I forgot how to fix it.

[freddy]

look for gpu scaling and maintain aspect ratio

[Swaffy]

Thanks. Got it. I thought I had to go in and change game files. Never thought of looking at my GPU settings.