On a MaxiSys Tablet click Settings then pull left side of screen up to scroll to bottom to see and click About and beneath serial number is your password.

 I am using  a PC and the serial number and password don't show up in the About section ?/ this is a piece of shit when the instructions can't even match the SW.  I sent a note to them but this fkr is going back if it isn't cleared up asap

 Did you E mail support with your questions or problems. I don't believe you can register code readers, USB cameras, and USB oscilloscopes for warranty. Only the Scan tools that have a specific update periods. You just save your purchase receipt as proof of purchase and contact your seller or Autel Support with proof of purchase for instruction for getting device repaired.