Canon MX420 - Manual (Page 17)

Step One
When the Register Printer and Scanner screen appears,
click Register Printer.
Registering the Printer & Scanner
This section describes how to register the machine on a Macintosh computer.
Registering the Printer & Scanner
17
Proceed to the section that relates to your operating
system for further installation instructions
Mac OS X v. 10.5.x / 10.6.x: Go to Step 2-A
Mac OS X v. 10.4.11: Go to Step 2-B