Wow, look at all those dang ICONS!! Holy Smokes!

Sorry, got carried away with the attachment....

Originally posted here by Danielsd
...I've been told that the disk was working for several days with out problems, and then suddenly that message appears.
Unfortunately, word of mouth can be one of hardest troubleshooting issues.

There is a chance that the message is true as it reads. That the disk is not formatted. Someone may have made everything dissappear either accidently or intentionally (partitions, resizing disks, etc).

Another time I have seen that is when the OS didn't recognize the OS on the other disk. Windows - *nix, etc.

cheers