Pardon my post that is OT, but here are some methods to kill your hard disk

1. Using Active Kill Disk, even for just Zero Fill or worse any of the "utter erasure" formatting methods that it proposes, on your Hard Disk and then suddenly shutting down your PC while it is still formatting and has not yet completed the task... So erstwhile make sure your PC's operation will not be interrupted while undergoing such use of this otherwise excellent software... Unless one wishes to literally kill his/her Hard Disk.

2. Exposing it to high G's, example is 1G or more, such as dropping them from some height.

3. Using your Hard Disks on a 12V rail that provides inadequate amperage, over some period of time.

And so on, and so forth...

uh oh sounds like dead external HDD already wen_loong7, that was also the response of my 500GB Maxtor External Hard Drive last year when it already died on me. Might be only, though, not actually confirming it's dead yet as i have not seen it.