Destroying Data on Your Hard Drive

Where to Recycle | Recyclables | Publications| FAQs| Sustainable Government

This information is provided for your convenience and does not constitute an endorsement of any product.This information is excerpted from the EPA publication Do the PC Thing for Consumers.

If you decide to clean your computer yourself, you can purchase software via the following commercial sites, or obtain them for free at shareware sites:

Commercial Windows Disk Cleaning Software

Freeware Windows Disk Cleaning Software (the following are available at

Macintosh Disk Cleaning Software

Is Data Really Gone?

Deleting something from your computer or email is similar to removing a card from the library’s card catalog but not removing the book from the shelf—the information is still in the library if you look for it. In the case of a computer hard drive, the file’s location information is removed from the drive’s index, but not from its place on the drive, so the file can easily be recovered by someone using sophisticated data recovery software.

Leaving Data Cleansing to the Pros

If you would rather leave the data cleansing to a professional, ask your refurbisher if they have a process to cleanse data from computers. Many of these companies use reputable disk cleaning software following U.S. Department of Defense guidelines. This software systematically overwrites all data and then verifies that this was done. Make sure that you have a good understanding of how the company will be addressing your concerns about data security if you will not be address­ing this issue yourself. You may even want to go so far as to ask your refurbisher for a written statement indicating the specific method the company will use to cleanse the data from your computer.