I tried my Killdisk programme disc but it didn't work as it was a freebe download for one use only; which I have used.
To save the hassle I bought a used 250 Gb off fleaby for a fiver which had been cleaned.
I reloaded it with a W7 disc I had, tried to authenticate it but it was out of date so it is back to a photo storage unit and little else.
I have two others for the internet so there seems little point in bothering it with anything else.
I dismantled the old hard drive and scorched the disc on the gas hob. A laser follower would have trouble getting over the blisters.
Thanks to everybody for the help and comments.