Hello Folks I found some time, did clone the faulty HDD mentioned in this thread and did the following the erase its contents before sending it back. BTW this is the HDD I am talking about: https://lh3.googleusercontent.com/-iXhU8z9nmfA/VRh0qOyCR9I/AAAAAAAACDE/oAWQk7N4iZ4/s0/Reallocated Sectors Count.png - used Gparted Live CD to format the HDD a couple of times as well as remove and add the partition table a couple of time - used Parted Magic Disk Eraser to fill the entire HDD with zeros using the dd command, however that stopped after about 5% since the HDD in the docking station went into sleep mode (grrr!) - used DBAN 2.3.0 with DOD short method to wipe the HDD, though that also stopped at about 8% into it since the HDD also went into sleep mode there - went back to Parted Magic and this time used the Internal ATA Secure Erase (wipe entire drive at the hardware level) method. This worked out and I got a two logfiles (basic and advanced) saying it did manage to wipe the HDD. However it also gave me warnings about the HDD becoming locked or bricked if the HDD was to be removed during the process. Since the process took only about 20 seconds the HDD did NOT go into sleep mode and the log files both confirmed that the wipe was successful I assume the hardware level deletion went OK. Now when I try to access the HDD in either Windows or Gparted or Parted Magic I simply cannot get it to mount or to be readable. Did I really manage to lock/brick the HDD? With the above methods used, theoretically how hard would it be for a support technician to try and find some of the data that was on the HDD? Can I trust the company I am giving this back to to not try and recover any of the data on the HDD? Should I ask them to give me a letter in writing that any of the data that was on the HDD will never be restored and no attempt at trying to restore the data will be made? All I want is the money back for the HDD (they already said I could go this way this guarantee only runs out end of next year) and use that in the shop to buy other goods. But I also want to know that the data on the HDD is gone. Yes I know that the only secure way of erasing it is physically destroying it, though I assume with the above procedure mentioned it should be fine, right? Basically I want to make sure as much as I can that the HDD will be very hard to nearly impossible to recover data from it. Is the HDD unlocking software that I could use with the HDD that is attached over a USB connection in a docking station? http://www.hddunlock.com/ says it can be done, though only with internal HDD and since I don't even have a desktop at hand this option is out of question for me. Would it actually make sense at this stage to try and unlock the HDD before sending it in, just to run Gparted or maybe Heidi Eraser on it? Perhaps I managed to really lock it after having formatted and nuked it, so chances of successful recovery should be nearly nil if they actually manage to unlock the HDD, right?