I switched a WD external drive from one computer to another. The 2nd computer didn't recognize the drive so I switched it back to the original computer and now it doesn't recognize it either. The drive wasn't dropped in the switch and I have made sure the drive's driver was current. Though I can't see the drive in "My Computer", I can see it as an unallocated drive in Windows Explorer". This is my 4th WD external drive to have gone bad in the last 5 years. Is there a better way to backup your computer? The drive had approx. 500 GB of photos on it.