Hello Rob, please note this is not an official way how to backup your data, but if you’ve backed up your original user/AppData/Roaming/eM Client folder e.g. the database folder or it’s whole content all you should have to do is to replace the directory with the current database in the user/AppData/Roaming folder which should allow you to see all your previous data from the database files.
However note that in order to restore successfully you have to use the built-in backup and restore option under File > Backup, which will create a database backup file, that you can restore from.
Regards,