If you were one of the many to receive a new computer this holiday season you might be wondering how best to dispose of the older one that’s served you so well over the years. While having multiple computers in the house has specific added benefits for each individual, if you instead wish to recycle or otherwise donate that old PC you’d be best served to ensure all your personal files and information have been removed first.

You might be quick to assume that a quick format of the entire drive or selective shift+delete on personal folders in question will suffice – it’s often now the case. Like removing the index from a book does not prevent an individual of skimming the pages of the book for the content, the same parallel exists with computers. To fully scrub and clean a hard drive requires any one of the numerous 3rd party utilities – such as Darik’s Boot and Nuke. However, were you aware that such functionality exists natively in Windows, starting in version 7?

Actually, the command line application is called cipher.exe and has existed for a number of years for managing Microsoft’s Encrypted File System or EFS. However, in Windows 7 Microsoft introduced an additional parameter that expands the functionality to include our specific interest.

Specifically the /w command line parameter: cipher /w c:\<folder_to_wipe>, replacing  folder_to_wipe with a directory or drive as appropriate for you under an Administrator Command Prompt.

Cipher will then write a random sequence of 1′s and 0′s to the location making it impossible to unearth whatever data existed in that location before execution. As their is no fall-back plan if you path in error, ensure you make no mistakes when using the cipher command!

Why use cipher over something like Darik’s Boot and Nuke above? Not only is the tool native to windows and does not require an additional download, most of the 3rd party tools operate on the entire drive in and all or nothing fashion. Excellent for wiping all of C but not so hot if you are gifting the computer to a friend of relative – as Windows would need to be completely reinstalled. Instead, something like cipher could be used on c:\Documents and Settings\<user> to securely wipe just your personal folder, leaving the rest of the file system intact and usable.