Serial #'s can be found under the battery or on the bottom of desktop computers.
this is your account password, you would have to type this in when you do Software Updates, or change System Settings. You may have chosen to have a blank password, if so, type "blank" in the password field.
If you have called AppleCare's Support Line, and they have issued you a Case # please enter it here.
Please provide all information for our Service Dept. on everything surrounding issues or problems you may be having with the computer.