So you want to sell an old computer? Well there are a few things you need to know first to keep your personal information private. We keep a lot of things on the computer that could be used for identity theft… tax returns, quicken records, internet passwords, etc so its important to make sure whoever inherits your PC doesn’t hijack this information.

Deleting Files Doesn’t Work

The solution isn’t to simply go into Windows and delete the files. When you delete a file all it does is remove the reference from your system, the information is still available on your hard drive until the data is actually written over by other file. So if you’ve ever found you deleted a really important file by accident you probably can still recover it with software such as GetDataBack.

And even once its been partially written over, you still may be able to recover it with more in depth techniques that are beyond my skill level but are certainly doable by a determined thief.

So How Do I Really Erase My Drive?

To fully delete the files you need a secure erase utility. These programs write over every block of the hard drive (sometimes several times) to ensure that your data is unreadable. These utilities meet NSA standards for data integrity as well as HIPAA and Sarbanes-Oxley so if we can sell the drive that had national secrets on it then it probably is safe for you as well.

There are countless programs out there that do this, ranging from hundreds of dollars to my price point - free. Here are some of the freeware and open source programs out there.

• Darik’s Boot and Nuke - This is a premade boot CD which I like (who has a floppy drive in their PC anymore?) which is very easy to use and open source. This is the program I use when I am looking to sell a drive
• Eraser - This freeware app works in Windows or you can create a boot disk with it. Has the best interface I’ve seen in Windows for a free program. Though its tough to delete all your Windows files if you are still in it, so if you want to completely erase the drive you’ll need to use the boot disk option.
• Secure Erase - Another freeware utility that is best used if you create a boot disk for it. There is a good writeup over at ZDnet on it.

Final Thoughts

With all the private and personal information we keep on our computers nowadays its important to make sure when you upgrade and get rid of that old hard drive you take some time to make sure your information is private. This is a pretty easy step to take if you use the right tools.