Frederick Marcoux
If you are on Windows, yes you have to backup/uninstall/reinstall v16/restore to upgrade. This is due to the new Callflow service that needs to be installed and this can only be done during installation on Windows.
uninstall does not delete the backup folder anymore but you can never be too safe. I also always recommend saving the backup file to a non 3CX folder.just take care you have done a complete backup from v15.5, save the file out of 3cx folders because uninstall delete all.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.