The following article is from Eastman’s Online Genealogy Newsletter and is copyright by Richard W. Eastman. It is re-published here with the permission of the author. Information about the newsletter is available at I enjoyed this article and hope that you will too.

“Do you ever have a need to delete all the information on your Windows computer’s hard drive? For instance, if you are about to sell or give your old computer to someone else, you might first want to remove all your personal information.

If you search on Google, you can find a number of stories about private data being retrieved from computers purchased on eBay and elsewhere.

Don’t let that happen to you!

Many people are surprised to hear that Microsoft Windows doesn’t delete very much when told to delete files. Windows simply marks the space as “available for reuse.” In other words, when you tell Windows to delete a file, your old information remains on the hard drive for an indefinite amount of time. It remains available until the operating system eventually writes new information in its place. In fact, even reformatting a disk with Microsoft’s format command will leave much information behind. This is true of hard drives, floppy disks, flash drives, ZIP disks, and other storage devices.
If you tell Windows to delete all your personal information, then give the computer to someone else, the recipient can use any of a number of utilities that perform “unerase” commands. That person can recover much of your personal information within a few seconds. That includes your checkbook register, your credit card information, last year’s tax return, or any other information you had on that computer.

Luckily, it is easy to wipe a hard drive so clean so that even the National Security Agency cannot recover one byte of your data.

First, the quick way:

Find a hammer and give the hard drive several good blows. That will destroy the disk drive’s data platters. For added insurance, obtain an electric drill and drill a few holes in the disk drive.

This “brute force” method certainly will destroy your old data but it seriously affects the resale value of the computer! In reality, there is no need to physically destroy the hard drive. You can destroy its contents much more easily through electronic means. By doing so, the hard drive and the entire computer can be restored to its original factory configuration and safely given or sold to someone else.


For years, many people have reformatted their hard drives and re-installed Windows before selling or giving away a PC. Indeed, this does make it difficult for anyone to later retrieve data from the computer but security experts tell us that even reformatting leaves behind some information. A reformat is not guaranteed to delete your personal information from the hard drive. A safer solution is to first wipe the hard drive clean, and THEN to reformat and install a fresh copy of Windows.

Wipe the Drive:

Darik’s Boot and Nuke (DBAN) is a free program that will wipe all data off a drive by rewriting new records on every sector of the disk. DBAN does not rely on Windows’ anemic erase command. Instead, it writes new data all over the disk, replacing every bit and byte that was on the drive previously. If that is not enough protection for you, DBAN will even fill up the disk with new records multiple times, writing different information each time. Each new record contains “dummy information” and it completely replaces whatever file was in that space on the hard drive. The end result is worthwhile if you believe that someone else will be using the computer in the future.

When I say that DBAN “will wipe all data off a drive,” I mean exactly that: ALL data. It removes your personal data as well as the Windows operating system and everything else that is on the hard drive. Once DBAN finishes, you will not be able to boot the computer. In order to use the computer again, you will need to have a CD of Windows or Linux to load onto it.

DBAN creates a self-contained boot CD-ROM disk. The program will do any or all of the following:

Quick Erase
Canadian RCMP TSSIT OPS-II Standard Wipe
American DoD 5220-22.M Standard Wipe
Gutmann Wipe
PRNG Stream Wipe

Those standards don’t mean too much to most of us but security experts all understand the differences. You can find detailed explanations of each by searching on Google. All except “Quick Erase” define methods of removing all readable information from a hard drive.

You also can specify how many “passes” should be made on your hard drive. For most people, running each of the above routines one time will provide sufficient protection. However, if your hard drive contains the Pentagon’s war plans, the combination lock settings for Fort Knox, or the documented whereabouts of Jimmy Hoffa, you might want to tell DBAN to run each of the above processes multiple times.

DBAN also works on all hard drives commonly found in desktop and laptop PCs, including XT, IDE, PATA, Serial ATA and SCSI disk drives. (Older PCs use IDE drives although Serial ATA drives have become more popular in the past few years. SCSI drives are mostly used in servers and very expensive, high-end workstations.)

DBAN does not run under Windows. You first download DBAN and use the downloaded file to create a bootable CD-ROM disk. Next, boot the DBAN CD-ROM disk. It loads its own operating system that looks similar to MS-DOS. You will also find it easy to automate DBAN’s wipe process: simply insert the disk and reboot the computer. DBAN will then automatically run the processes that you specified. This is especially useful if your employer is selling or giving away a lot of used computers and you need to wipe the hard drive of each one.

The best thing about DBAN is its price: free. Darik’s Boot and Nuke is open source software; you can even download the source code to verify its operation or even to improve it, should you wish to do so.

Every PC technician should have a copy of Darik’s Boot and Nuke, as should anyone who plans to sell or donate a computer. Darik’s Boot and Nuke is available at

I have used Darik’s Boot and Nuke a number of time and am pleased with its performance. It’s not bad for a free program! Other disk wipe programs I have heard about, but have not used, include:

Kill Disk, available in a limited free version as well as in several more comprehensive commercial versions for $40 to $60 at

Acronis Drive Cleanser, a $61 commercial product, available at

These commercial products tend to be easier to use than the free Darik’s Boot and Nuke but all the programs produce the same result: a completely wiped drive with no possibility of recovering old data.

If you have a need to only erase a few files, using DBAN would be overkill. A number of programs will safely delete individual files without wiping the entire hard drive. One of the more popular and respected products for Windows computers is available free of charge:Heidi Eraser. It is found at



1 Comment on Wipe Your Hard Drive Clean

  1. LInda Gartz says:

    Thanks for passing on this very informative post. I’ve sent it on to several friends. Important to know. Also, thanks for dropping by my blog and commenting. Always enjoy hearing from you!

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