Before you dispose of a computer or return a defective hard drive, make sure your personal information is securely destroyed.  Deleted files can be recovered.  Even formatting the drive does not make your data unrecoverable.  Short of physically destroying the drive, you need to securely destroy the data.  I use methods recommended by the U.S. Department of Defense.  Only a handful of world class experts can recover information destroyed by this method.  Afterwards the hard drive can be returned to you, or I will donate it to a charity or recycle it.  If you have the original Operating System and Drivers CD's, these can be reloaded.