I am constantly warning people not to sell on hard disks without doing the proper procedures. For me, the required amount would be to smash it up with a large hammer. However, if you’re selling it on, obviously that’s not a practical idea. In this post I will explain how to prepare a hard disk to be sold on, and that is not to format it.

Firstly, you’re going to need to get DBAN (Darik’s Boot and Nuke, surely one of the best apps in the world) from its official site. If you’re not quite sure what to download, don’t panic. Just click on the applicable link to your boot media. That will direct you to a download page, where a file will be downloaded to your computer. If you have selected the one to do it via a floppy disk or USB flash drive (I beg of you not to do the USB flash, as I have never tried it and I have heard it is not particularly good), merely execute the program and it will guide you through the recommended steps (then skip to the paragraph after next). For the CD/DVD option, you will find that you have downloaded an ISO file. An ISO file is basically a group of files that are preconstructed, ready to be put on a disk immediately. To burn it to a CD/DVD, get CDBurnerXP, a program that is surely better than Nero or MagicISO, and it’s completely free, too.

Open up CDBurnerXP, select ‘Create Data CD/DVD’, then click on the ‘File’ menu. Then select ‘burn disc from ISO file’. Once the ‘Write ISO Image’ dialog appears, click on the browse button (the one with the three dots) and find the ISO file you downloaded, then click OK. After that, click ‘burn disc’, and your disc will begin burning. Don’t worry about fiddling with any other settings.

Once all of that is done, insert your disk into your computer. If any windows appear asking you what you want to do, just close them. Leave that disk in and restart the computer. As your computer restarts, it should detect your CD/DVD/Floppy and start the program. It may say ‘Press any key to run CD’, in which case do as it says. If, however, no prompt appears and it loads Windows, restart again and enter your BIOS. This may sound challenging but actually it is very easy, just look for something that says ‘Press [key] to enter setup’ or ‘Press [key] to enter BIOS’ or similar, and press the key (there may even be an option to select boot device, in which case tap that and select the medium you want to use. Usually it will show the brand of the boot device in the name, if not, try going through them until you get the right one, rebooting after each attempt to regain you access to the screen.). Then your BIOS will come up. Now, this may look confusing, but it is very easy. Keep pressing the right arrow key until you get to the arrow that says ‘Boot’ or similar. Then go to ‘Boot Device Priority’ or similar by going up and down the list, and then pressing enter. There should be a number of them, but go to the one that says ‘Primary Boot Device’ or ‘1st Boot Device’ or similar, and select the device you want to use. Usually it will show the brand of the boot device in the name, if not, try going through them until you get the right one, rebooting after each attempt to regain you access to the screen. Make sure, however, to put the item that was the primary before into either a free slot, or the slot where the item you selected before used to be. Now, go to exit (you may need to press esc first, if pressing the right arrow key does nothing) which is usually the last option, keep pressing the right arrow key until you get to it and select ‘Exit and Save Changes’ or similar. Your computer will then restart, and it will boot up the media that has DBAN on it.

Once DBAN has loaded, you will be presented with a screen that looks like the one to the right. Press F3 on your keyboard to see the commands that you can input, but don’t select the ‘autonuke’ option, or press the enter key, as this will not wipe your data enough so that fraudsters and other prying eyes can’t get to it. Once you have pressed F3, you will be given the commands that can be used with DBAN. DoD is a method which the Department of Defence in the USA use to wipe their computers, and it is pretty good, but the Gutmann method is much better, and if you use that fraudsters won’t have a chance in hell of getting their hands on any of your private data. I would always say to use it as it is practically impossible for any fraudster to access your data if you use it. So, just type ‘gutmann’ without the quotes. Then the wipe will begin.

Once the wipe is finished, you will be told to shut down. Make sure to remove the disk before doing, if you still have it in. And voilá, your disk is erased, and ready to be sold free of any remnants of any data that may have been left behind if you had merely formatted it.

LGW has suggested that I write out the bells and whilstles DBAN has to offer, and naturally I am obliging. So here are some tips and stuff that you probably didn't know:

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SYSLINUX.CFG is the file that tells DBAN what to do if it does not get assigned a specific command. This file is included in both the floppy and the ISO version of DBAN, but naturally for the latter you will need an ISO editor. Get CDBurnerXP as mentioned earlier (or WinRAR) and open up the iso instead of burning it (just create a new data session and open it). Then you can add and remove files from the image, including SYSLINUX.CFG. Once you have opened it (with a plain text editor) it should be pretty straightforward from there. This particular file is interesting, but it is pretty extravagant to edit and useless for most users because you can simply type the commands in the prompt. (Note: this file is within the IMA itself, if I recall correctly.)

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The following IDE options can be stated by the user at the on boot. For example, boot: "dban ide0=autotune hdb=noprobe".

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CD and inlay labels can be found in the "MEDIA_STICKERS" directory (if you are running the CD version).

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Here are descriptions of the various wipe methods (commands can be found with F3)

The fastest choice, Quick Erase, does one pass of zeroes on the drive. This is relatively easy to recover with the right equipment.

The second choice, RCMP TSSIT OPS-II, uses the techniques recommended by the Royal Canadian Mounted Police Technical Security Standards for Information Technology in Appendix Ops-II: Media Sanitation. This gives eight passes, which is probably good enough to outsmart just about all people wanting to recover the data.

The third choice, DoD Short, is based on the American Department of Defense Standard 5220-22.M. This only does three passes, but even that should outsmart most people wanting to get their hands on your data.

The fourth option, DoD 5220-22.M, is a different technique, but obtains a similar result to the RCMP wipe.

The fifth option DBAN offers is the Gutmann wipe. If you are going to sell on your hard drive, it's always a good idea to invest your time doing this. It is nigh on impossible to retrieve anything whatsoever from a Gutmann wipe.

Finally, DBAN offers a PRNG Stream option. This method overwrites the drive with a stream from a Pseudo Random Number Generator (PRNG). You can choose four passes, or eight passes.

That's a good help for those of us not so savvy on using linux commands