Can you teach an old dog (non-upgradeable All-In-One) new tricks (add a new CPU)?

My old DELL is a DESKTOP-195DLP5 all-in-one. It cannot be upgraded to Windows 11. 

I want to continue to use the Dell monitor, bypass the Dell CPU, and instead use the HP Mini Pro CPU so I can upgrade to Windows 11.

An HDMI cable was connected from the Mini to the spare HDMI input on the Dell All-In-One.

The Windows 11 Welcome and Set up Screen did not appear.

In the Windows 10 software Settings screen, the HP Mini Pro does not appear as a connected device available to select.  When I tried “Choose a Device” and the ‘Add a Device’ option, the DELL did not find the HP Mini Pro.

However, the HP Support Assistant page appeared on the Dell monitor and recognized the Mini Pro as a connected device. This gives me hope there is still a way to bypass the Dell CPU and use the HP Mini Pro CPU. I just can’t figure out how to do it! 

Maybe the spare HDMI ports are just for a second monitor. 

Dell support declined to provide assistance due to the age of the Dell.  Since there may be other Dell All-In-One users trying to save money (and the planet) by continuing to use perfectly good monitors, I hope the Dell community can help.