Eddie On Everything

How to Securely and Completely Erase Your Computer’s Hard Drive

June 8, 2006 on 1:33 pm | In windows xp, privacy, linux, software |

Getting rid of that old computer? You might want to consider either hanging on to the hard drive or making sure that it’s been completely erased before you do so - your personal data may be at stake.

If you’re like most computer users, you probably have a few files on your computer that you don’t want strangers getting ahold of. Perhaps you have a spreadsheet containing your budget and salary information. Or maybe you have a Word document that contains your credit card number or your Social Security number. Worse, you might have a copy of your Quicken or Microsoft Money, or maybe even a copy of last year’s tax return.

In fact, if you use online banking or shop online, it’s possible that even your Internet Browser’s cache folder contains information that can be used to steal your identity.

It may sound frightening, but the fact is that simply deleting these files will NOT prevent others from later accessing them. There are a number of data recovery tools available that can be used to retrieve this lost information, even after it’s been overwritten by other files.

For this reason, I’ve always destroyed hard drives by drilling holes in them then soaking them in water for a while before setting them out on the curb. But what if you want to donate your old computer to charity, or sell it on eBay?

Before doing so, you’re going to want to download a copy of Darik’s Boot and Nuke boot disk. (It’s completely free.) This disk is used by making either a bootable floppy or CD, and then booting the computer with the disk in the drive. The program will use sophisticated multiple-write algorithms to ensure that your data cannot be recovered by even the most advanced recovery techniques.

This program is used by both the Department of Energy and the National Nuclear Security Administration, so you know it’s secure.

Always ask a repair center to return your drive to you, even if they say it’s going to be destroyed

Don’t trust that computer repair centers will actually destroy your hard drive - these places are notorious for reselling the damaged goods to wholesalers, who then refurbish them and re-sell them on the open market.

Case in Point: A June 2006 story on MSNBC tells the tale of how exactly that happened to one extremely dissatisfed Best Buy customer:

One year ago, Hank Gerbus had his hard drive replaced at a Best Buy store in Cincinnati. Six months ago, he received one of the most disturbing phone calls of his life.

“Mr. Gerbus,” Gerbus recalls a stranger named Ed telling him. “I just bought your hard drive in Chicago.”

Gerbus, a 77-year-old retiree, was alarmed. He knew the old hard drive was loaded with his personal information — his Social Security number, account numbers and details of his retirement investments. But that’s not all. The computer also included data on his wife, Roma, and their children and grandchildren, including some of their Social Security numbers.

In June 2005, when Gerbus took his computer to Best Buy for repairs after a hard drive crash, he knew the drive was a potential hot potato. So when a clerk there told him it had to be replaced, he asked for the damaged hardware back.

No dice. The replacement was done for free, under warranty, and Gerbus was told the old drive had to be sent to a repair center in Chicago to fulfill warranty terms.

“I asked in the store on two or three occasions. … I was very concerned,” he said. “But they said ‘we can’t give you the old one because it’s under warranty.’”

Gerbus said he was assured that, after verifying the warranty, workers in Chicago would drill holes through the drive and make it unusable.

Gerbus’ hard drive did make it to Chicago. But instead of being destroyed, it landed in Ed’s hands. In January, Ed tracked down the Gerbus family at the couple’s winter home in Florida, and placed that disturbing call.

“The only way he would have had my Florida number was if he had my hard drive,” Henry Gerbus said.

Ed told Mr. Gerbus he’d purchased the drive at a flea market for $25, Hank Gerbus recalls.

It is a HUGE mistake to trust someone else to destroy your sensitive information. As you can see from Mr. Gerbus’ story, despite Best Buy’s assurances, the drive was never destroyed. Don’t become a victim of identity theft.

Download a copy of Darik’s Boot and Nuke (DBAN) Here.