We recently had a client who wanted to replace one of their employee’s computers. In this process, I asked (and they wisely accepted) if I should destroy the data on the old computer’s hard drive after taking a backup of the necessary data to transfer to the new PC.
Often times, nonprofits and small businesses don’t realize how much valuable information is stored on – and can be retrieved from – old computer hard drives. For example, what did your organization do with your 5-year-old accountant’s computer when you retired it last year? Did you throw it away or recycle it? Did you give it away?
If you do not securely erase content on your old hard drives, then data such as that stored on your accountant’s computer (think: bank account numbers) can easily be recovered with the right software and forensics expertise, even if you “deleted” the files!
Whenever you typically delete files, the data is actually not removed. Instead, a “flag” is set, telling the computer that the space that the data occupies is available.
The data is still present, unless it is actually overwritten by a new file (which could happen in mere minutes from the time you delete a file, or it could possibly never happen).
In this short blog post, I will briefly explain two ways you can securely discard your old computers.*
- Destroy the hard drive
This option is as easy as it sounds – destroy it! But if this is all you do, then you better be sure that it is actually destroyed! Aside from manually taking it apart (this is not recommended, and is time consuming), here are some creative ways you can destroy your hard drive:
- Take a sledge hammer, and beat it (very hard) several times
- Hammer nails, or use a screwdriver to drive screws, into it.
- Burn it, and then proceed with one of the above options
- Drop it (several times) from a 3rd story (or higher) window
- Securely erase all of the data on the hard drive
As this option is the more likely, more professional, scenario for most of our readers, this is the one I recommend. My favorite tool is a Linux utility called DBAN that comes with a CD called Ultimate Boot CD. Simply write the Ultimate Boot CD ISO to a CD, boot your computer with it, navigate to the DBAN utility, and let it do its job!
DBAN works by overwriting every bit on the hard drive (even the parts of the hard drive that contain deleted data), so that the data is completely erased. It is a tried and true method for removing secure information, and fast!
* Disclaimer: We do not guarantee that any of these options are safe or failproof. You should always use sound judgement, be safe, and obey the laws in your jurisdiction as well (especially if you consider burning the hard drive and/or dropping it from a 3rd story window)!