HELP! NOT MOUNTING: HD-HC500 U2 R

[ettaro]

   

The above-stated 500 gig HD has been working fine.  No problems.  I went into my studio this morning to transfer a bunch of video files from my laptop (running vista business) onto the drive.  Then, I safely removed hardware and plugged the drive into my studio computer (running vista home).

 

Well, the HD just spins and clicks and the red light blinks, but nothing comes up.  After a good long period of time, a drive shows up with a different drive letter than has always been assigned to this drive, and windows tells me "you must format this drive before using it."

YOIKS!!!!!

 

That's not cool.

Did everything on this drive get lost?    How can this be?  I really need to get this data and make sure it's backed up.

Is this a normal problem for these drives?  I hope someone can help.

Thanks.

Sam Ettaro
Pennsylvania