How to Delete Your Data According to Your Level of Paranoia

It’s finally time to get rid of your notebook, but what about all that data you have stored on your hard drive? Is it safe to just reformat and toss it? Will anyone actually take the hard drive out from the dump? It may scare you how easy it is to retrieve your personal files.

“For me, recovering data from a disposed hard drive is trivial, even if it has been destroyed. I buy them for a buck or two apiece on eBay and run forensics on them just to sharpen my craft,” said Paul Henry, vice president of technology evangelism at Secure Computing Corp. “I am amazed at the amount of personal data that is still on these hard drives.”

Henry warns that some big-box retailers have been known to sell hard drives taken from older computers for upgrades and replacements on eBay. That means your credit card data and social security numbers could fall into the hands of the wrong people. He suggests that users always ask for the hard drive back.

Sufficiently frightened yet? Fear not, because our guide will help you wipe the digital slate completely clean.

Paranoia Level 1:

Reformat

Henry argues it’s a misconception that reformatting your hard drive will erase it forever, but if it’s just a folder of pictures you and your girlfriend took together, a reformat should do the trick—at least when it comes to hiding those files from casual users.

1. Find your Windows Vista/XP Recovery Disk
2. Boot to your CD-ROM
3. Delete your current partition
4. Choose to create a new partition
5. Reformat your hard drive
6. Reinstall the operating system

Paranoia Level 2:

Wipe your Drive with Software

Maybe you want to sell the hard drive on eBay, without having to worry about casual users retrieving any of your data. Or maybe you want to get rid of sensitive corporate information. For these cases, Henry suggests drive-wiping software. Windows XP/Vista users should download freeware such as Eraser (www.heidi.ie/eraser), which will overwrite data—including file names—or even clear the names of all old files, The program uses Darik’s Boot and Nuke (DBAN) disk option. DBAN itself can also be downloaded from dban.sourceforge.net for free, and can be booted from a USB key.

1. To run Eraser on a Windows PC, place a blank CD in your
   CD/DVD drive, then open Eraser’s folder in the Start menu
   and “Create Boot Nuke Disk.”
2. Boot to the CD and let the program run.

Paranoia Level 3:

Shred It Like a Nervous Accountant

You’re being investigated by the government and you need to get rid of all of your data, quickly.

Henry says the best option for these cases is a hard-drive shredder. That’s because some forensic data miners can actually retrieve data from hard drives using “magnetic transmission” techniques that “look at magnetic fields on the drive itself, and can tell if something has been overwritten,” Paul explained. “The forensics experts can then recover the data.”

A company called Semshred (www.semshred.com) will shred your hard drive for you, starting at $7 per drive for up to 25 drives, although there is a $50 minimum charge.

Paranoia Level 4:

The Sledgehammer Approach

Finally, when all else fails, Paul Henry suggests taking the hard drive out to the garage and “beating the hell out of it with a sledge hammer. Destroy the platter, drill holes in it, burn it. Some people even microwave them.”

1. Buy sledgehammer
2. Place hard drive on garage floor
3. Cover eyes with protective goggles
4. Pound hard drive repeatedly.