I want to use SyncToy to backup data folders to external USB Drives. I want 2 backups. When I remove the first drive and plug in an identical 2nd drive, SyncToy thinks it is the same drive and finds no files to backup. Sometimes (But not always by any means) I have had it work after a reboot. This time however a few days after the 1st backup, it ill not recognise the 2nd drive as a different drive and says there are no files to sync when a directory clearly shows there are. Any ideas please ??