I have a number of old PCs, notebook computers and external hard drives that I have mothballed, but that I had not yet taken to the recycle shop here in Seattle. Although I had deleted all the files from them*, the drives still need to be scrubbed. (Yes, I could physically destroy the drives with a hammer, but that is messy and I wanted to avoid it).
*Deleting files just change some of the pointer information on it. It does not remove the file from the drive.
I finally found a solution: a military grade drive erase program called Darin’s Boot and Nuke program (DBAN). It’s open source software and free for personal use, but it does take a little work to set up and use. (Here’s a review).
First, download a program and use it to burn a boot file onto a DVD. Then set up the computer with drives to be erased, to boot from this DVD (not from its hard drive). The program then lets the user select the hard drive or external drive that should be obliterated (overwritten). OK, time to pay attention. Verify twice, erase once (along the lines of the tailor’s motto ‘Measure twice, cut once’). The warning says ‘This program irrecoverably destroys data’ . Yes. That is what I want.