When you are done with your old computer and before you give it away or sell it on e-Bay make sure you have securely removed all sensitive personal information from your hard disk.

The information on the hard disk is stored in microscopic particles. These electromagnetic particles are facing one direction (ON) or the opposite direction (OFF). Each individual particle is either ON or OFF. Grouping 8 particles together creates one Byte of data representing one letter, number or special character. The files on your hard drive are a collection of Bits and Bytes organized together following a specific layout.

For more information that you will ever want to know about hard disk technology go to Caltech

Deleting a file from your hard disk does not actually get rid of the file from your hard drive, but rather makes the file “status deleted” for your operating system to reuse its physical space as needed.

Deleting a file is very much like taking a letter you receive via “SNAIL MAIL” and dropping it in the garbage. The piece of paper in the garbage is still intact, then it is move to the dumpster an in the process may get more or less damage and sometime mingle but retrievable by someone looking through the dumpster.

For that very reason when you are about to part with your old computer you must make sure you thoroughly remove all personal information from your hard disk, or make it very difficult for an expert with sophisticated Data Forensic equipment to make any sense of the information stored of the hard disk.

This operation is very similar to using a DOD approved cross cutting shredder or using an incinerator on discarded paper documents.

NOTE: Crackers, Hackers and Identity Thefts start with your discarded material. “Dumpster Diving” 50% of the time

“MIT Laboratory for Computer Science Graduate Student (LCS) Simson Garfinkel and Abhi Shelat performed a study looking at hard drive sanitization practices and found a widespread lack of awareness about how to effectively remove sensitive data from hard drives before recycling or discarding them” (see full story here)

Securely destroying all the information from your hard drive. The information included below is targeted at Windows users. If you are a Linux User then you should not need any help.

PART I – CREATING THE DISK ZAPPER FLOPPY DISK

1) Download the Windows Tools DiskZapper.

2) Download the “diskzapr.flp” floppy 1.44MB disk image (The file is also located in the download section of our site).

3) Download the “rawrite2.exe” DOS floppy image writing tool (The file is also located in the download section of our site).

4) Create a directory in the root of your C: drive example “tmp”

5) Copy both files ““diskzapr.flp” and “rawrite2.exe” to the c:tmp directory

6) Open the “tmp” directory and double click on the rawrite2.exe. (a DOS shell window will pop up prompting you for a filename.)

7) At the prompt enter the diskzapper floppy disk image you have just downloaded “diskzapr.flp”

8) You then will be asked to enter the floppy drive letter 99.9% of the time it will be “A” (try “B” if A does not work)

9) Insert a blank formatted floppy disk in Drive “A” and press ENTER.

10) Once the software has completed writing to the floppy all 80 tracks it will exit. You are now ready to wipeout your hard drive with you brand new Disk Zapper bootable disk.

11) Label “Disk Zapper” WARNING Use With Extreme Care – This Disk Will Destroy All Information on Hard Disk When Used.

WARNING: You, the user, are solely responsible for data security. TNTmax strongly recommends that you perform a backup of all personal data contained on your system prior to performing this procedure.

WARNING: TNTmax will NOT be held responsible for any data loss incurred during this process. The information describe below will result in the completed destruction of all information from your computer hard disk – use at your own risk with extreme caution.

PART II – WIPING OUT YOUR HARDDRIVE

1) Insert the newly created DiskZapper in the Drive A of the computer you want to wipe clean

2) Reboot the Computer with the Disk Zapper in your Drive A

3) Upon Booting from the Disk Zapper Floppy Disk you will be presented with a “Warning Screen”

4) Enter Erase at the Boot: prompt and press ENTER.

5) Wait until the process is successfully completed this will take some time (Time used is proportional to the size of your hard drive)

6) Repeat 3 more times, starting at steps 2.

7) DONE.