"Following on #2,685 and #2,686 - if you even open something on your computer the only way to be certain that it can never be recovered is called a blow torch. I know that when I've had to bin a computer I've always removed the hard drive and destroyed it (an ax works very well). I do remember an IT professional friend telling me that when he had new recovery software he'd sometimes go down to the dump and pick up a couple of scrapped computers - said it was always "interesting" to see what people thought they'd deleted on those hard drives." S2 #2,687
Many OS' ago, perhaps all the way back to DOS, issuing a command to delete a file affixed a marker to that file, a sigma iirc.
The marker designated the file as deleted, BUT !
a) It would remain until it was over-written, &
b) could be recovered with simple software which found the designated file name, and removed the marker (sigma?).
Those that are serious about wiping a twirling platter computer hard drive (HDD) clean may wish to try the suspenders & a belt approach.
The protocol in S2 #2,687 works, but may potentially leave discernible data.
To dodge that bullet, triple-overwrite the drive, before following that protocol. If it has text on it:
- overwrite it with video, movies, broadcast TV, whatever.
- Then overwrite that with text, until there is no room on the drive for even one additional alpha character.
A complication is newer technology now offers SSD, no motor, no twirling magnetic platter.
Pulverization may be adequate for that, if a vat of acid to completely dissolve the drive isn't available.
I want to ensure that all my personal data is completely unrecoverable before I sell or dispose of my computer. So now, I'm looking for guidance on how to...
techcommunity.microsoft.com
& a note on secure disposal of confidential hard copy / paper documents:
A shredder might seem secure disposal, BUT ! it may only make the docs into jigsaw puzzles.
To securely terminate paper docs, set them aflame, reduce them to ash, insuring all applicable laws and safety procedures are adhered to meticulously. Then stir the ash thoroughly.