Reformatting/Erasing Samsung M3 1T Portable Hard Drive

[Riotgirl91]

Hi - I have run into a road block in my efforts to erase and reformat my Samsung Portable Hard Drive (HX-M101TCB/G). It was originally used for our Windows laptop - which is now dead - and I want to erase all content and reformat to use with my Mac. I have gone to Disk Utility, selected the only partition within the disk, gone to the 'erase' option, selected 'Mac OS Extended (Journaled) from the drop down menu option, under 'security' I have selected the 'safest' option to completely erase the content, then gone to start the process and it comes up with a notice saying 'Secure Disk Erase failed with error: couldn't open disk' - how do I fix this?

Thank you so much for helping me out!

 

[Lutfij]

Have a go with this suggestion:
https://discussions.apple.com/thread/5812340?tstart=0