I have recently had to reformat my internal hard drive as a result of which my external drive was not recognized. Using Disk Managment I allocated a drive letter to the external drive so that it appears in My Computer but the external drive file system is not recognized though there has been no change in my computer hardware or OS - XP SP2. It worked fine before. The PC asks if I wish to format my external drive. Of course I do not because I would lose all my data. Thanks in advance.