How to securely delete files or erase the whole hard disk

Jephe Wu -

Objective: securely delete files for Windows and Linux or erase the whole hard disk
Environment: Windows and Linux

1. delete files only
a. use free GUI open source tools eraser -
note: When I use version 6.0.7 under Windows vista, it cannot start, saying 'Eraser has  stopped working', you can solve it by deleting C:\Users\Jephe\AppData\Local\Eraser 6\Task List.ersx.

b. use sdelete at

c. use DOS-based tool 'secure erase' at

d. freeraser -

e. use shred for Linux

2. erase the whole hard disk
a. use ISO CD

b. use free version of Active @ killdisk at

c. use dd or ddrescue command
dd if=/dev/zero of=/dev/sda