Wiping your Hard Drive

It has been quite a while since I have posted on my blog.  I guess I just let my work take over my life!  I've been working on a cloud computing project that, when finished, will be offered to the world.  We are in a trial phase right now, but when done, will provide both Linux and Windows servers for people to do whatever they would like with them.

I have had several computers during my lifetime.  I can remember a Commodore Pet computer that stored data on a cassette tape!

I thought I was BMOC when I purchased a Commodore 64 with a 1541 disk drive.  Man how things have changed!  I was first in line when Compaq introduced a business-aimed computer with 64MB of RAM and a whopping huge 500MB hard drive (don't ask me what I paid for this).

I have owned several computers since the Compaq, which I recently donated to charity.  Currently I have a Dell laptop and a clone desktop machine at home.  The Dell is a screamer!  I use it all the time.

My Dell laptop has 4GB of RAM and a 320GB hard drive.  We've come a long way baby!

Over time, when I would sell or donate an older computer to charity, I would keep the hard drive.  I, having quite a thorough security background, know that it is quite difficult to erase all the information that you store on your computer's hard drive.  Performing a simple format on the hard drive will make it so that the operating system (Windows in most cases) will not see any data on the drive, but the data is still there.

If you are using Windows, Windows will mark certain parts of the directory structure to indicate that the files are no longer there, but it does not erase the files.  Data recovery programs get their claim to fame by restoring the changes to the directory structure and presto!  All of your files are back.  There have been a few cases where I have deleted a file by mistake, or the one time I deleted a directory structure by mistake.  I am happy that there are free utilities that will easily restore this data to my very happy viewing!

So, if you are selling or giving away an older computer, how can you insure that the data on your hard drive is really gone.  Some people tell me the only true way to insure that the data is gone is to destroy the hard drive -- maybe they are right.

So the above picture would probably work.  However, besides destroying the hard drive, the laptop would be a complete loss too!

I had an unfortunate situation a little while ago when my older laptop developed a short in the power cord.  I didn't realize what was happening until my laptop rebooted one day.  I found the short and fixed the power cable, but then my laptop would not boot.  Come to find out that the shorting cased power fluctuations in my laptop that destroyed its motherboard, hard drive, etc.  It had become a brick!  So I still have that computer's hard drive.  I know the data is still on it, but the controlling circuitry is fried!

What can be done to get all of your precious data off of you old computer's hard drive?  There are two things that need to happen:

1. Need to boot the computer with an operating system other than the one on your hard drive.
2. Need to run a utility to delete the data from the hard drive.

There is a cool utility called Darik's Boot and Nuke.  This utility will do the above and do it nicely.  You can download it as an ISO file which can be opened up by any good CD burning program like Roxio.  When you burn the ISO file to a CD, it will create a bootable CD.  When you place this in the CD drive of your old computer and turn it on, the CD should boot a small operating system and allow you to select from a few different data destroying programs.  If the CD doesn't boot you will have to push F12 or whatever key your computer uses to access the BIOS, and then disable all devices from booting except the CD drive.

Once you boot the CD, it will display several options, the first of which is an algorithm used by the Department of Defense.  This program will write numeric patterns (like 0's) over the whole surface of the hard drive.  Depending on the size of your hard drive, this process could take 2-3 hours.  The program will make a minimum of  three passes over the hard drive.

At the completion of running the program, your hard drive should be in a state where you can safely sell or donate it to another party and rest assured that nobody will be able to get at your data. 

One last note, Darik's Boot and Nuke (DBAN) is not the only product out there that will securely remove data from a hard drive.  There are commercial and open source, but I talk about this one since it is free and it creates a bootable CD automatically.

Hope you have a great holiday season!

Til next time, and I hope that it is sooner than the last time,
Bill