Ubuntu.
I just spent a week trying to gain access to a failed mybook essentials external hard drive that my girlfriend owns. Literally tried everything, some data recovery software, checkdisk, testdisk? - different power cords (of the same spec) and usb cords, different computers, hooking up directly before realizing it was hardware encrypted, and searched desperately for a matching pcb board… hers was rare and expensive.
After spending hours reading different forums I found one guy who had success using Ubuntu, a different operating system. I downloaded it, burned to dvd, and booted the computer from it. It gives you the option to “try Ubuntu” from disk without changing anything on your computer. Once it was up and running I plugged the drive in, and 30 seconds later had all her files. I hastily copied them over to a healthy drive, and then erected a shrine to the Ubuntu gods in the corner of my room for nightly prayer sessions. For whatever reason, they had no problems recognizing the drive, unlike Windows.
For the record her drive would power up, and if it did show up in explorer, it would load incessantly before listing one of several different failures, and then dissappearing completely. Or not show up at all. It was in disk management most of the time, and listed as working properly… but you could never get it to open. Testdisk would bring back nothing but continuous read errors during scans.
Hope this helps someone else avoid blowing several hundred dollars at a data recovery center.