We are decommissioning around 40 Dell desktops. We would like to donate them but drives need to be wiped. What's the best approach to wipe them all as efficiently as possible?

Is it standard practice to reinstall the OEM OS before donation or is this generally taken care of by the recipient? If I need to reinstall the OS, what's the best approach for imaging 3 different models?

6 Answers 6


Standard practice depends on how good a wipe you need.

Fast wipe: Write one pass of zeros across the whole drive.
Thorough wipe: Write alternating passes of zeros and ones across the whole drive at least twice.
DoD Wipe: Write multiple (I believe the standard is 7?) passes of alternating ones and zeros across the whole drive.

A tool like dban is probably the best way to accomplish this on a large number of systems.

(Note that this assumes traditional (spinning magnetic) hard drives. SSDs are Different and Special)

Re: the OS, Typically I turn over the media and license keys to the organization I'm donating to, but leave the machine blank in the state it was after the wipe was completed. This lets the recipient decide what OS they want to install and go about it however they wish (and if the machines wind up in a technical-training setting they may want their students to install the OS themselves).

If you install an operating system that requires a license (Windows) ensure that the license is with the machine (this covers your legal posterior).

  • 2
    +1 for keeping license key with the machine. I picked up some machines from a surplus outfit once only to discover that someone tore the OEM Window's CoA sticker off of them. Annoying.
    – user62491
    Mar 21, 2012 at 20:16
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    +1 Wipe, leave blank, dump on donee. Write-off! =]
    – Chris S
    Mar 21, 2012 at 21:14
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    @aseq If your data is sensitive enough that only NSA-Approved destruction techniques will suffice you shouldn't be donating your machines anyway. Once the decision has been made to donate any of the methods above are more than sufficient to prevent recovery unless the attacker substantial resources. I appreciate your paranoia, but in the real world tax write-offs for donating hardware are very attractive and the residual risk is very small.
    – voretaq7
    Mar 21, 2012 at 22:20
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    At the risk of shilling, we've discussed data sanitisation and disposition a few times on security.se. One example I was involved with: security.stackexchange.com/questions/11316
    – Scott Pack
    Mar 22, 2012 at 0:08
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    One pass with zeros is enough. Mar 22, 2012 at 1:48

For wiping data I would use DBAN http://www.dban.org . Making an image of three diferent models its tricky. I know that Acronis had a tool for doing image of diferent configuration (image without drivers). I would simply do images of three models with clonezilla.


Refer to my question here on security.SE. To reimage them I suggest using a solution where you use TFTPboot for windows. Your computers will then just boot from a prepared image over the network (so you don't need to put disks in every single one of them).


Check out Darik's boot and nuke... you can make a few CD's of it pre-configured to startup, nuke the hard drive with a DoD level wipe, and come back later to a finished clean PC.

I would provide media, but leave installation to the new owner, not your problem.


If you have a Linux liveCD, you can generally do a Good Enough(tm) job of wiping the data via:

dd if=/dev/urandom of=/dev/sda

which covers the entire drive (including partition table) with random junk. It's theoretically possible for a hardcore data-recovery specialist to get your data back after that, but if you're trafficking in data that's sensitive/important enough to warrant it, chances are you won't be allowing the disks outside of your extremely-secure armed-guarded facility to begin with, at least not intact.

However, the safest way to ensure that a hard drive won't have any information that gets into someone else's hands is to simply not provide the computer with the hard drive. Pull the drives and donate everything else; hard drives are cheap and unreliable (i.e. failure-prone) enough that anyone who wants to use the computer will probably be better off buying a new drive anyway.

This way you'll also still have the drives in your possession in case you discover that some of the data on it actually was quite important. (I highly recommend labelling the disks after you pull them so you can keep them straight for this reason. Obviously you do NOT want to wipe the drive first if you're going to do this...)


To be honest with you you can probably donate the computers without the hard drives though you may receive some bad karma. I have seen computers donated with all kinds of missing parts. It just depends on whose receiving them from you and what organization your donating them to. Just act like you don't know anything about computers when you donate them lol. Kind of a mean move but hey they are still giving computer parts for free. I would follow vortaq7's advice for wiping if you want to be an angel about it. I would be paranoid if the data was extremely sensitive. Also consider how much time it takes to do a DoD wipe on just one large hard drive and you might be ripping those hard drives out in no time. Save your moral judgements if they are directed at this post please :-)

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