Windows 10: External monitor is not working with my Windows 10 laptop

I have a small HP laptop with Windows 10. Everything works except I cannot get an external monitor to work. The external monitor used to work with this laptop. I know the external monitor and HDMI cable still work because I tried with a different computer.

With my Windows 10 laptop I go to Control Panel -> Display -> Screen Resolution. I see it sees a second monitor with or without the HDMI cable plugged in. My laptop has no VGA port.

When I try to extend the display when the HDMI cable is connected, I see "The display settings could not be saved. Please try a different combination of display settings."

I tried using Fn + F4. I tried using Windows button + P. I tried rebooting. I tried closing the lid of my laptop.

This laptop and external monitor combination used to work -- months ago. I have not applied any updates since then. I have not installed anything since then. The physical cable is the same. I do not know why it would stop working. I do not use this Windows 10 laptop on the internet.

In the Control Panel for Screen Resolution, there are drop down menus. Some of these values show the brand of the monitor when everything is working. With my Windows 10 laptop that does not have the external monitor working, the Screen Resolution drop down menus do not detect the monitor brand. With my Window computer that works with the external monitor, the brand name is detected and displayed in a drop down menu in the control panel. The non-working laptop refers to a VGA device in one of the values in a drop down menu.

How can I get my laptop to extend or project the display to an external monitor?

:)