the display on my monitor only covers about 3/4 of the screen

[Bluesman50]

up until about ten days ago the display on my new monitor covered the full screen, but something happened and now it does not and I dont know how to correct it

[Chimney_83]

Greetings @Bluesman50,

Welcome to HP Forums and Thanks for the post. 

I understand that you are facing an issue with the display on your All-in-one computer. Is that right? Don't worry, I will be happy to help you.

Have you tried any troubleshooting steps on your own?

Do you have any external devices connected to your computer?

Recommend you to shut down the computer. 

Turn the computer ON and keep tapping ESC or F10 on your keyboard repeatedly. 

This will boot your computer to the Startup menu or BIOS. 

Check if you get the display on the whole screen. 

If you get the display on a full screen in BIOS. Then it is a software issue. 

Please perform a system restore and this will resolve the issue you are facing. 

To perform a system restore, please refer to this HP Article. Follow the steps mentioned under "Restore your computer when Windows cannot start normally" in the article. 

This will revert the computer back to the previous settings. Select the date when the computer was responding fine. 

Keep me posted. 

If the information I've provided was helpful,

Please give us some reinforcement by clicking the "Accepted Solution" and "Kudos" buttons,

That’ll help us and others see that we’ve got the answers!

Good Luck.