Magnolia won't install modules after I change magnolia.repositories.home

I'm using magnolia 6.2.20 and Derby and I want to run a new magnolia installation on my server.

When I change my magnolia.repositories.home to point into a new folder, I don't see this screen to start the installation, I'm only seeing that my content is gone:

How can I force a new magnolia installation on my server, where this installation is stored and why I don't see the magnolia installation?

Thank you,

Please check that you can see new path in the log file on startup.

In all likelihood you have changed the path in wrong file (there's overlay system in place to check multiple files to assemble final values by combining them together as described here).
Alternatively, if you want to drop old repo and just start a fresh, you don't need to change repo home at all and just delete all artefacts from existing installation (folders: repositories, tmp, cache, modules, logs)