Render old hard disk data irrecoverable.
It has always seemed ironic to me that when you accidentally delete a file, it's often tough to get the file back. However, it seems that when you delete a file on purpose, recovering the deleted file is often all too easy. Simply deleting a file doesn't mean that it's gone for good. There are plenty of Undelete utilities that can easily revive supposedly erased files on a workstation. But what do you do when you want to permanently erase a file? Short of taking a ball-peen hammer to the hard drive, here are a few suggestions.
Going beyond formatting
You can format a hard drive to erase data, but someone could easily unformat the hard drive and then gain access to all the files that once existed on it. I routinely used my computer to manage both my personal finances and the finances for my businesses. Everything from credit card numbers to Social Security numbers to tax records were on the hard drive at one time, and could easily be salvaged if all I did was format the drive.
If I sold my PC and the buyer decided to unformat the hard drive, he or she could do a lot of financial damage or even engage in full-scale identity theft. In fact, there have been reports of people who purchased used computers at thrift stores for this very purpose. There are more than 700,000 cases of identity theft reported in the United States each year, many related to personal computer use.
A while back, the U.S. Department of Defense began to realize just how vulnerable to disclosure the data on old hard drives was. It therefore passed DoD 5220.22-M, the hard disk clearing and sanitizing standard. Basically, this standard describes how Defense Department hard drives should be reformatted so that there's no chance of recovering any previously existing data.
Obviously, the Windows Format command doesn't conform to this standard yet. I wouldn't be surprised to see a secure format built into the next Windows operating system. In the meantime, though, if you want to securely format a hard drive, you'll need to purchase a third-party secure format utility.
There are several utilities on the market. One popular choice is Active@ KillDisk. This product comes in a free version or a professional version. The free version performs a semi-secure format, while the professional version, which sells for $29.95, conforms to Defense Department standards.
Another competing product is East-Tec Sanitizer. The standard version of this product allows one person to format up to 10 hard drives for $29.95. For $199, up to 10 technicians can format an unlimited number of hard drives. There is also a free trial version that allows one person to reformat one hard drive.
Another company, Eraseyourharddrive.com, is offering a unique approach to secure hard drive formatting. Unlike the other solutions I've mentioned, the Eraseyourharddrive.com approach is Web-based. The user purchases a single-use license for $23.95 and uses it to reformat his or her hard drive in a secure, DoD-compliant manner.
Although the company plans to offer discount pricing for organizations needing to format multiple PCs, I got the impression from the company's Web site and press releases that the service is being primarily targeted toward individuals who need to reformat a single PC. In my opinion, if you're formatting only one PC for personal use, then it's probably better to save yourself the $23.95 and just download a free copy of East-Tec Sanitizer.