Unable to change default program

This does not work:

However it can be added to open with menu:

RE: Set as default. You have to run 7-Zip File Manager. 7zFM.exe - run as administrator.

https://www.7-zip.org/faq.html

Then choose the desired extensions and decide to keep for current user or all users.

From my settings app:

Hi,

There is a workaround in another thread that works. I hope that helps.

Note: Especially and only 7-Zip needs what @Callender rightly suggests.