16 August 2007

How to really erase a hard drive

By Jim Pinto

Do you have an uneasy feeling when you give away your old computer that perhaps someone could recover precious passwords and sensitive old files? If you don’t, you should. It is quite easy to recover old “deleted” information from a hard disk.

You can spend hours going through your hard drive deleting all the files and documents, but Windows only removes the shortcuts to those files, which makes them invisible to users. Deleted files still reside on the hard drive, even if you empty the “Recycle bin.” Almost anyone can reinstate your files.

Formatting the hard drive is a bit more secure than simply erasing the files. However, formatting a disk does not erase the data on the disk, only the address tables. It makes it more difficult to recover the files. However, a fairly savvy hacker can recover most or all the files.

If you are preparing a system for retirement, you should consider complete removal of all data. Besides identity theft, data theft may leave you or your company liable under federal and state laws, with criminal penalties.

There are many programs you can buy to completely erase your hard disk. But, if you are in the mood for a little hacking, or have access to a geek, you can use a utility that is already on your computer. This is “Secure Erase,” a set of commands embedded in most drives built since 2001. It is disabled by most motherboard BIOSes; but you can still use it if you really want to (weblink below).

Some people say there is another, simpler way. Just take out the hard disk, and destroy it—break it with a hammer. Let whoever you are giving it to buy a new hard-drive—hey, they are cheap enough.

Related links:

• How should I erase my hard drive before I give it away?
  http://ask-leo.com/how_should_i_erase_my_hard_drive_before_i_give_it_away.html
• How to REALLY erase a hard drive:
  http://blogs.zdnet.com/storage/?p=129
• How to Completely Erase a Hard Disk Drive:
  http://www.webopedia.com/DidYouKnow/Computer_Science/2007/completely_erase_harddrive.asp

Behind the byline

Jim Pinto is an industry analyst and founder of Action Instruments. You can e-mail him at jim@jimpinto.com or view his writings at www.JimPinto.com. Read the Table of Contents of his book, Pinto’s Points, at www.jimpinto.com/writings/points.html.