If a person registers a drive then sells it to someone, does the warranty transfer? Does the new owner have to do anything?
As far as I know, you will not be able to register the drive under your name, but, you can still apply for a replacement, if the drive is under warranty.
The warranty is linked to the drive serial number.
Note: If you wish to register the drive under your name, the other person can unregistered the drive, this will allow you to register the drive under your name.