Securely wipe hard disk drive data

The siren has sung and you’ve finally succumbed to her call: You’re the proud owner of a shiny new PC; a faster, better SSD; or a bigger, better hard drive. It’s time to toss your old equipment in the trash and start playing with your new toys, right? Not so fast.

First you need to clean the data off your old drives so you don’t become a victim of identify theft. Simply deleting the data off your hard drive doesn’t actually delete it; it basically just hides it from immediate view. To truly hide the data on your storage device and protect yourself against identity theft, you need to take much more drastic (and time-consuming) measures that overwrite your drive space with ones and zeroes. That’s where this guide comes in.

Different technology and scenarios call for different tools. We’ll identify the best secure-erasing utility for every job, no matter what type of drive you’re using–even USB flash drives. If you want to erase only specific files, we’ll show you how to do that, too. Best of all, every solution discussed is free.

Before You Begin

Back up your data! Once these programs get ahold of your drive, you can’t go back for a forgotten file. And if you’re going to erase a laptop’s hard drive, be sure to plug the notebook in before you start. If the power goes out in the middle of a disk wipe, it could spell disaster for the drive.

Let’s talk terminology. Drive-wipe utilities specify how many “passes” the software makes. Each pass signifies a complete overwrite of the data, so a utility that makes three passes overwrites your data with ones and zeroes three separate times. The more times you overwrite your data, the less likely it is to be recovered. Some utilities support “Gutmann”-level protection with 35 passes, but three passes is enough for the U.S. Department of Defense’s “Short” specification and for numerous militaries around the globe.