hdclone free edition

cloned my windows xp hard drive to a Seagate external hd that already had some back up info on it. after the cloning process was complete my computer no longer recognizes my ext hd being connected to my computer and I cannot access my saved data. my device manager shows it to be connected and working properly. I did make a boot disc to use after I install new hd in my windows xp pc. wondered if I,m doing something wrong.