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How to wipe personal data from cell phones and PCs

Protect yourself from identity theft

December 27, 2007 12:00 PM ET

Computerworld - Before you recycle your old computer, cell phone or smart phone, make sure that you wipe it clean of data. If you don't, your personal life could be laid bare. Worse, you could become a victim of identity theft.

But wiping your device clean of data may be harder than you think. Here are details about how to do it for cell phones and PCs.

Cleaning up cell phones and smart phones

With cell phones and smart phones like BlackBerries, you need to worry about more than your data -- make sure that your account has been terminated. If not, others will be able to make phone calls from your device, and you'll be footing the bill. So double-check with your carrier that the account has been terminated before you donate or sell your phone. If you've switched your account over to a new device and deactivated the old device on that account, check your bill carefully to make sure that the old phone isn't somehow still using that account.

Next, erase all of your stored information, including your phone book, any stored incoming or outgoing text messages, and memory of incoming and outgoing phone numbers, e-mails and so on. You can do this manually, one by one, of course, but if you do, there's a good chance you might miss some. And it can also be exceedingly time-consuming. So check your phone's manual for how to do a complete reset. A reset will wipe your phone of data and restore it to its factory settings.

A superb resource for figuring out how to reset cell phone data is put together by ReCellular, which buys, recycles and refurbishes wireless devices. Its cell phone data eraser site gives detailed instructions on how to erase data from many different makes and models of cell phones. Just choose your make and model, and you'll be able to download specific instructions for resetting it.

Wiping PCs

Just deleting files isn't good enough when you are going to recycle your computer. It's quite simple for anyone to restore those deleted files, even if they're no longer in the Recycle Bin. In fact, even deleting files and reformatting your hard disk won't completely do the trick. Someone knowledgeable enough and dedicated to the task will be able to restore your files, even from a reformatted disk.

Think there's nothing to worry about? You couldn't be more wrong. In 2003, two graduate students at MIT's Laboratory for Computer Science bought 158 used hard disks on eBay and other places. From those hard disks, they were able to discover 5,000 credit card numbers, personal and corporate financial records, medical records and personal e-mails.

Only 12 of the 158 hard disks had been properly cleaned of their data. Approximately 60% of the hard drives had been reformatted, and about 45% of the drives had no files on them (the drives couldn't even be mounted on a computer) -- yet the students were still able to recover data from them, using a variety of special tools. For details, see the news story from MIT.

What can you do? Get a disk-wiping program, preferably one that meets the U.S. Department of Defense's standards for disk sanitation. These programs will overwrite your entire hard disk with data multiple times, ensuring that the original data can't be retrieved. If you use them, be patient, because it can take several hours to wipe the hard disk.

Computerworld features editor Valerie Potter vouches for the free Darik's Boot and Nuke, which, unlike some competing programs, worked smoothly on the old Windows 98 machine that she recently put out to pasture. Download the software, which then creates a boot disk that wipes everything on the hard drive. It can be used with floppy disks (remember those?), USB flash drives, CDs and DVDs. A similar program that has gotten good reviews is Eraser.

If you've got a Mac, you can use Apple's built-in Disk Utility or download a third-party application like Mireth Technology's ShredIt X 5.8 ($25, free trial), which lets you shred single files as well as wipe your local hard drive, network hard drives and CD-RWs.

Everything clean? OK, now it's time to sell, donate or recycle your equipment. Find out what to do in "Out with the old: What to do with your unwanted tech gear."

Read more about Hardware in Computerworld's Hardware Topic Center.



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