How do you change the screen format in Windows?

I turned on my laptop today and then suddenly the format was just changed. I've already looked it up on the internet, but somehow I get stuck. Could we maybe tell someone how I can reset the format?
Thank you for all the answers

You want to change the resolution. This is e.g. Described here:
https://www.heise.de/...99144.html

Install driver if necessary, then set the resolution accordingly in the display settings.

You have to left click on the maud then click on customize and then click on the picture or whatever you want and then on save (That's the way it is with me)

Hope I could help you