How do I make display on external monitor match physical size of external monitor screen?

[chiggi64]

There are no selections offered here that match my problem.  I have an external monitor connected (just got that done).  It is fine except the display on the external monitor doesn't match the physical size of the screen on the external monitor.  There is 1 3/4" of black at the bottom of the display. How can I expand the display to match the size of the screen? 

My computer is a Lenovo; I have Windows 11 and Microsoft 365. My external monitor is HP1965.

Thank you.

[banhien]

@chiggi64 

What is your Lenovo ? What is your monitor and How do you connect them ?

Regards.

[chiggi64]

My Lenovo laptop is an IdeaPad S145-15WL Model 81MV.  My monitor is HP LP 1965.    They are conneced by HDMI cable.  I've been on live chat and phone with Lenovo, HP and Microsoft for days and the only thing the expert tecs where able to suggest is that there is incompatibility between Lenovo and HP.  I have the laptop monitor screen resolution set to the recommended settings of 1366 x 768 and the external HP monitor set to recommended settings of 1280 x 1024.  When I have only the laptop screen on, the display fills the full screen but as soon as I get the external monitor on, the display on the laptop monitor shrinks to a square size from a rectangular size and there are inches of black space on either side of the display.  

One of the things I have noticed is that all of the instructions I can find on the internet are for Windows 10 or Windows 7 and when they tell me to do something like right click on desk top and go to sceen resolution; I do it and there is no screen resolution there.  I am baffled.  It used to work perfectly with my last computer which was an HP.  If you have any ideas; I'd be glad to hear them.  Thank you for answering.

[banhien]

@chiggi64 

Now I can see they do not have same ratio, the machine use 16:9 but the monitor use 10:8, you won't get a match. 

Please set up your external monitor as Extend  mode and both monitors should work independently

                 https://support.microsoft.com/en-us/windows/set-up-dual-monitors-on-windows-3d5c15dc-cc63-d850-aeb6-...

Regards.

[chiggi64]

I  have tried the extend display many times; just did it again.  When I click on extend display, the external monitor goes to a solid green with bottom task bar but no display.

Should we then assume that they just are not compatible?