What do you store on your computer’s hard drive? If you’re anything like me, you probably keep just about your entire life stored on your computer. If you’re also like me you probably change computers on a regular basis, in my case, sometimes once or twice a year. Or maybe you use multiple computers, or a shared computer? This is probably something everyone can relate to on some level.
When you give a computer away, or move to a new computer, chances are you’re keen enough to delete all of your old information and files off the hard drive. Maybe you’re even alert enough to re-install the computer’s operating system or to ‘refresh’ the hard drive image from a restore disc.
What you might not realize, is just how easy it is for the next owner of your computer to recover everything you thought you’d deleted. Recovering ‘deleted’ files is actually quite simple! The reason for this is because when you delete a file, your computer is simply marking the file as deleted. Even if you empty the trash can (or recycle bin for you Windows folks) the files are still stored on your computer. Only when your hard drive needs more space are the files written over by new data.
I found out how easy it is to recover information when I had a hard drive mess up a few years ago. I accidentally corrupted the partition table (uh, the table of contents) on my laptop hard drive and lost all my files–years worth of accumulations of music, videos, pictures, and documents. I was absolutely mortified! After a little digging, I found a program called “Boomerang Recovery” which not only recovered my deleted files, but recovered several gigabytes of files that I did not recognize… probably files from a previous owner of that laptop! This software recovered files I didn’t even know I had stored on the computer.
This made me think–if I could so easily recover all of these files so easily, what would stop anyone from doing the same when I give the computer away? I started to realize that a person could recover not just information about me, but all of my friends and family as well! It’s a scary situation but a very real possibility!
There is hope however! If you own a Mac, securing your hard drive before parting with your old computer is very simple. Simply pop-in the OS Installation Disc and re-boot into the installation / recovery mode. Cancel the install and use the “Utilities” menu to activate the Disk Utility program. This allows you to erase your hard drive securely by writing zero’s over the entire data structure multiple times. Depending on how much free time you have, you could erase your hard drive to the standards of military-grade security! I recommend performing at least a “7-pass” secure erase. This will probably take at least 12 hours, but is well worth the peace of mind that nobody can come along after you and recover your ‘digital life’. I’m sure that there are methods of doing this for Windows PC’s as well, perhaps Windows 7 has a similar utility built in…
You can use these methods to securely erase flash drives and portable hard drives as well! You should always securely erase the hard drive of any computer you’re giving to people you don’t know or trust. The same goes for cell phones too–while you can’t neccessarily perform a 7-pass secure erase, you should at least try to restore the phone’s operating system before you give it away to strangers–even phone data could be recovered and used for unworthy purposes.
So now you know how those lovely agents on CSI find all that incriminating digital evidence!
