Originally Posted by Brian-bmw

You probably have the MKIII navigation computer, and here is how to tell for sure. Go to the main menu. From there, click on the "SET" or "SETTINGS" selection. The version of your nav computer and OS will appear on the upper right corner of the screen. The first digit tells you which version of the nav computer you have, and the last two digits tell you the OS version. If the first digit is a "3," you have a MKIII computer. If you have a MKIII, then the newest OS version is 3-1/63.