I think that you can install several versions of MC on the same computer. On Windows this is what I would do:
- back up your library
- uninstall MC19 with the options box unchecked (don't delete the registry entries)
- install MC23
- restore your library with the settings box checked
This method works for me when I switched from MC23 32bits to MC23 64bits. I have also done this between MC21 and MC23, but MC23 was crashing if the "restore settings" box was checked. So I have restored my library and manually changed the settings.