I performed the steps as outlined in this Wiki (from the parted magic command line)
and managed to issue a 'SECURITY ERASE' command, which appeared to clear the drive. However..
Still the same thing as before when Windows boots up, it reports 'media is write protected' when I try and make a partition table in Computer Management.
Ugh.. it's like we're back to keying in Cylinders, Heads and Sectors in our BIOSes to get drives to work (yes, I'm that old)
Too much hassle for a supposedly next generation storage device for sure.