Ah, I may have read your post too quickly.
Have you previously uninstalled versions 17 - 21, and you see their directories only under AppData/Roaming/JRiver? If so, then my instructions are wrong. I assumed that you still had the older versions installed, and hence, it would be easy to run them, since you would still have their shortcuts in Windows.
If the above is the case, and you just have those orphaned directories, then the first thing you should do is check under "Options>File locations" in MC22 to be sure that none of the directories are pointed at one of the old installations. I find that often the "Cover Art" directory, for example, remains pointed at the previous version when I install a new major version. Sometimes the "Temporary files" directory also remains pointing at an old version.
If the "Cover Art" is pointing back at an old version you will want to copy that directory to the MC22 directory structure, and then change the setting in "Options>File locations". You can just change the "Temporary files" setting without copying anything.
Then you can delete the version 17 - 21 directories under AppData/Roaming/JRiver.
If you haven't uninstalled the previous version of MC, but no longer have the shortcuts to run them, should just be able to run "Media Center xx.exe" in each installation directory such as "C:\Program Files (x86)\J River\Media Center xx" and then follow my previous procedure. You should still check the "File locations" settings first though. You should be able to uninstall through the Windows Control Panel.