Fixing Screen Size in Emulator/Rom

[msh89]

I have a Raspberry Pi3B+ running Retropie and I'm having trouble with the screen size and resolution when I start a game. The resolution is fine when on the main menu but when starting a game I'm only seeing maybe 10% of the game as if it's overblown. I've attempted several times to find the answer on different websites and forums. I've had trouble once before and was able to fix it once but now I don't remember.

What I've tried already:

1. Pressing A when the game is loading and changing the resolution for the emulator. Can't seem to find the right one.
2. I saw an answer somewhere to run the command sudo raspi-config. Is that the command, nothing else?
3. I also saw an answer to go to Settings and choose "Adjust Resolution" but can't seem to find that.

P.S. If you can give me instructions on how to upload photos I can show you what I mean. You can seriously only upload photos of 1mb or smaller?

[mitu]

Please add some more details about your setup, as detailed in https://retropie.org.uk/forum/topic/3/read-this-first.

Pressing A when the game is loading and changing the resolution for the emulator. Can't seem to find the right one.

Just remove any custom resolution and leave the game/emulator running with the default resolution. Check if you haven't got a 'render resolution' configuration and remove it also.

I saw an answer somewhere to run the command sudo raspi-config. Is that the command, nothing else?

raspi-config sets the global resolution, used when starting the Pi, but it doesn't affect the individual game/emulator resolution if you're changing it from the runcommand menu.

I also saw an answer to go to Settings and choose "Adjust Resolution" but can't seem to find that.

Maybe in the Configuration Editor ?