This article wasn't initially very popular - It's a shame really; as the message is important, but I didn't convey it at all well. -So I've given it a rewrite; and hopefully the importance of the issue under analysis will be clearer:

When you sell your old hard-drive on ebay; make sure you erase all data from it. - Your personal data, passwords, bank details, ...In fact your identity in total is probably contained on your hard-drive; and unless you erase it somebody else can and might use it in your stead to gain access to your money; or even to borrow money, buy goods, obtain hire-purchase, etc, in your name and leave you to pick up the repayments. Your hard-disk is a goldmine; don't let other people mine it before you've removed the precious content or the loss to you will be tragic.

Allow me to explain further: When you delete items from your computer by clicking "Empty the Recycle Bin"; the item is deleted from the Windows registry but is not erased from your hard disk. - Therefore the computer no longer registers the item(s) as being "there", and given time will eventually overwrite the data in that space on the disk with a different file - NOTE: The data is not erased; only the computer's reference to the data is erased - So although your computer no longer sees it, it is probably still there and fully recoverable! If the disk has been used on a company computer then it's usually password-protected, but the security isn't exactly Fort-Knox standard, and is fairly simple to bypass; especially if the drive is formatted in FAT32, although even NTFS doesn't always present too much of a barrier to access company data and the complete contents and usage details of the workstation which the disk came from. - And the fact that you've put all the company data in the recycle bin and emptied it doesn't mean that you've erased it; as seen above.

There's another point too; It annoys me, and probably countless others, that I/they have to erase all that data myself/themselves - Especially when it's the only disk in the computer and I switch on with a genuine Windows CD in hand ready to install the operating system, to be greeted by Windows 98, ME, or 2000 with all of the wrong drivers installed which could damage my hardware. -Especially if it then goes to a password screen... I then have to reboot and go into the BIOS to change the boot-sequence to first of all attempt to boot from the optical drive... blah

There are numerous programs that will erase a hard-drive beyond almost all recoverable degree. Formatting is good but still leaves a security risk; some data is still recoverable even after a format. You could format the disk 10 times; that would make it extremely difficult for anyone to recover anything; but there are programs out there that will write unintelligible gobbledygook across your formatted disk, which will hide any traces of recoverable data to such an extent that it's virtually impossible to recover even with the most advanced equipment. Webroot Window Washer is one that I use which springs to mind. (I don't work for Webroot and I don't sell Window Washer; it is just one suggestion from a large number of similar programs.)

Identity theft is on the increase. Don't become a victim by sending people your life on a platter: At very least format any old hard-disk before you sell it on; or you could be selling someone the key to a fortune at your expense for a few pounds. I'm actually surprised that some unscrupulous individual hasn't tried to buy every secondhand hard drive for sale on ebay in the knowledge that someone somewhere hasn't bothered to format or clean their old drive and has unknowingly offered their identity to the highest bidder. Maybe it's already happened? Don't let it happen again - and most importantly don't let it happen to you.