On 10/21/11 8:24 AM, James B. Byrne wrote: > I have a HDD from a laptop that is being returned for > repair replacement. I wish to remove certain files before > sending the laptop back with the HDD. boot a Linux rescue USB or CD to a shell prompt dd if=/dev/zero of=/dev/sda bs=65536 this will as quickly as possible zero the entire disk, effectively erasing all files. with modern disks, a single pass of zeros is about as good as it gets, the old multipass secure "DOD" erasure was designed for antique disks that had bits the size of sand grains. even this fast single pass of zeros will take an hour or so to wipe 300gb. or, if you've connected this disk to a linux PC with a USB adapter or whatever, do the same command, replacing sda with the correct physical drive (no partition numbers) -- john r pierce N 37, W 122 santa cruz ca mid-left coast