My Book Essential External HD 3t used with windows 8 64 bit

My computer will not recognize my external hard drive.  I have two of these drives and one is recognized.  I have tried changing the connections to no avail.  My guess is that the drive is dead.  Is there any way that I can retrieve the information on this drive?

Are you connecting the drives at the same time or just one at  time?


I have tried both ways.  They did work togeter for about three months.