When the Restore Backup Tool has been clicked, a pop up will appear on your screen.  Here you can select a backup that you would like to restore to.  You will have to provide the Database Name to confirm the restore.  Once you have done this click the blue Restore Backup and Overwrite Database Button. This will cause the selected Act! Backup to be restored and overwrite the existing Act! database . All data changes made since the backup was created will be lost.