Once in a while I want to sell or give away a hard disk or a whole system. Although nothing important was stored on it in the first place I want to be sure that my data is wiped out completely. It is more of a privacy issue than anything else. Just in case some weirdo wants to restore my data. I am not concerned that a well-equipped organization with fancy three letters wants to get my data. There are a bunch of films where forensic experts in high-tech war rooms dissect the last bit of a destroyed disk and find the essential data to save the world. Really. Maybe I am too lazy to be paranoid but if I was such an organization I would not bother to dissect a hard disc and spend a lot of resources to find out the information I need. In most cases if you ask kindly enough people will cooperate. Social engineering is the right term for this approach I guess. Go to someone they trust and build a trustful relationship to them and there is the information you need. Case one You have a disk you want to wipe out and you have a running system where you can attach the disk to. In this case I use DiskWipe (http://www.diskwipe.org/). Simply download it and you are good to go. Be careful which disk you choose because all you disks are shown. A second approach might be just to encrypt the data with truecrypt (http://www.truecrypt.org/) or any other encryption software. If your key is long enough and you throw it away a potential cracker will have a hard to get your data. I still prefer wiping out the disk because it makes more sense to me. Case two You want to wipe out the boot disk of a system. For this case I used Parted Magic (http://partedmagic.com/doku.php). You can download an ISO File from their site and install it on a CD/DVD or USB stick. I myself prefer the USB Stick because using a CD/DVD seems too wasteful for a temporary solution. For creating a bootable USB stick I used UNetbootin (http://unetbootin.sourceforge.net/). Download the tool, run it and install Parted Magic on the USB stick. Afterwards you can boot the system from the USB stick. Parted Magic gives you a set of nice tools. Go to System Tools > Erase Disk and wipe out the disk. Make sure you choose the right one. That’s it. Critics might say that writing a bunch of zeros to the disk is not enough. There are tools which write up to 35 times to the disk. But again security measures are always a tradeoff between the threat level and the security level you need. If you want to absolutely sure just destroy the disk physically with a sledge hammer. That is an at least what I do when I have no further use for the disk.