The key thing to remember (as an earlier post in this thread
) is not to go next/next/next - but read each page and when you get to an options choice (left hand side, not right where the next button is) select this and make sure you tick download to device and computer. It will give you a choice of where you want to save on the computer (see later). I left it as the default which worked in terms of Mapsource locating it.
Then complete the rest of the download instructions and the update starts. Depending on the speed of connection this can be a long time and take place automatically in three parts. You then have the latest map on the Zumo and in Mapsource.
That is a very important piece of information. It is not difficult to do the above, however, it is not intuitive either.
Unless someone explains the above to you (as Cooperman did above, or as the Garmin rep explained to me on the phone), you will not have a 'matched set' of maps on both your GPS and your laptop computer.
The good news is that if you did not follow the above procedure the first time you downloaded the maps - by this I mean if you only downloaded the maps to your GPS, not to your laptop computer - it is very easy to go back and fetch them a second time for installation on your computer. Just sign in to your 'myGarmin' account, and download the mapset a second time. You can download the mapset as many times as you want until you get it right.
As you probably know already, it takes a long time to download the mapset (it is about a 2 gig file), so, start the computer up just before you go to bed and let it do the work overnight. Leave the GPS connected to the computer with the USB cable - once the mapset is downloaded, the computer will then go to the GPS to retrieve the unlock code needed to enable the maps on MapSource. If the GPS is not connected to the computer, you will get a prompt at the end of the download process to go fetch the GPS and connect it.
If the GPS is connected to the computer during the download process, then when you wake up the next morning, you will see a pleasant message telling you that all the work is done and the newest mapset is now installed on your computer.
Last suggestion: REMOVE all the previous mapsets (using the 'Programs and Features' function from the computer's control panel). That will ensure that you don't accidentally create routes on your laptop using an out of date mapset.
Michael