My Book light just moves up and down

My 500 gig external hard drive doesn’t seem to load, it doesn’t get a drive or even show up in my computer, light on hard drive just moves up and down and doesn’t stop.  How do I fix this?  I have tried on Vista and Win7 computer.  I have a ton of data on this drive that I absolutely need (was my back up drive).  Powers on fine, can feel it moving but just doesn’t stop the light going up and down and can’t seem to access it at all.  I need your help!!

I am using My Book Home Edition

Did you try a different USB cable? Does the drive show in Disk Management?

Joe

I have switvched USB cables.  Another important note, the light moves up and down even when not connected to the computer.  I just power it up and the light comes on and then starts moving like there is activity.

Also tells me USB device not recognized on both the Vista and Win7 computers.