WD Mybook Essential lock

have a Western Digital Mybook Essential external HDD 2TB which is password locked. Well with my old OS it showed me that is unlocked, but as I changed the OS it's showing that is locked, I've already tried all the possible combinations of passwords that I could remember but no luck. I'm usin Knoppix now to access the HDD somehow but I don't know how.

1. fdisk -l doesn't show the HDD.
2. lsusb is showing me that it's connected

In /media/sr1 appears the WD Unlocker mounted, but the HDD itself is not showing. If I can't access the HDD by bypassing the lock then it's even possible then to retrieve the data from it if I format the locked HDD?Because as I've read the hardware locked devices have a formating technique after which the data cannot be retrieved(Is this true?).