I was running Defragmenter and one of my slave hard disk showed up as "Unmounted Volume" with no drive letter assigned to it. The drive is 120GB and I have not had a problem at all with it. I've been reading around in forums on-line but I have not got an answer to my problems or anything to try yet. I can analyze and defrag the "Unmounted Volume" hard disk, but I still don't see any of my information. What caused this?