In Windows 7 go to Desktop. Right click in the desktop area.
You should see a choice for Screen Resolution. You can change it there.

I use less than maximum resolution for ease of reading.

Since you didn't say what OS you are using my advice may not (probably won't) apply.

I'm using Win 7 as long as I can as I'm certain that 3/4 of my apps won't migrate to Win 10 or later. (I hate & despise "upgrades")