My Passport connects to PC as internal drive and requires formatting

I have a My Passport 500GB external drive which worked perfect until yesterday - I connected it to my PC and to my Laptop, both WIN 7, and in both computers I got the message that the drive in internal drive and windows require to format it before it can be accessed. I do have some important data saved on the drive so Formatting would be not acceptable. Any idea what is the problem and how can I overcome it??


Have you tried using a data recovery software? That will be the best options since the partition might be corrupted.