Purging: Removing the data at a more fundamental level, either using the drive’s own controller electronics to carry out the task, or by degaussing (placing the drive in a machine that generates a strong magnetic field). The National Institute of Standards and Technology’s Guidelines for Media Sanitization (PDF NIST Special Publication 800-88) recommends three different ways to “sanitize” a hard drive:Ĭlearing: Overwriting the entire drive with new data so that the old data is no longer readable by a computer, although it may be possible to retrieve some data in a laboratory using signal processing equipment and specially trained personnel. Files that have been deleted and not yet overwritten can easily be “undeleted” using freely available undelete utilities such as Recuva. Even if you bypass or empty the recycle bin, the data is not physically deleted: The space on the disk where the data is stored is marked as available for reuse, but the old data will remain there until the space is reclaimed to store new information. When Windows “deletes” files, it simply moves those files to the recycle bin so that they can be easily retrieved. There are also numerous state and federal regulations, as well as specific industry regulations such as the health Insurance Portability and Accountability Act (HIPAA) and the Payment Card Industry Data Security Standard (PCI DSS), which require personal and other information be securely deleted before storage media are discarded or reused. As a quick Google search will confirm, there’s no shortage of stories of valuable data found on hard drives bought second-hand or salvaged from the garbage.Īn incident like this can be embarrassing and harm the reputation of your company – and if confidential business information is leaked, it could have serious negative financial consequences.

What happens to the confidential data on hard drives and other storage media in your organization when you replace them? It’s a vital question to ask – because unless the data is completely erased, there’s a good chance that it could come back to haunt you.

Clearing a hard drive