Originally Posted by ArthurKnowles
...It looks like the update includes a product key to install the software. So what is the unlock code to download maps that I hear so much about?
When I bought my first Garmin, a 2610 it included a software product called "MapSource". (I now have a 2820, and think a Mapsource program disc was included but I am not sure, because I already had Mapsource installed on my PC to be able to use the 2610, but I digress).
The software is a mapping program that you install on your PC. You need an unlock code to be able to use it. That is still the case today if you want to upload the latest maps and do route planning on your PC and then load waypoints and routes to your Garmin GPS. Relative to older StreetPilot GPS devices like my 2610, the Mapsource software was also used to load sections of the detail maps to a compact flash card that was used to hold the detail map data. So if you didn't have an unlock code, you couldn't load maps on to your 2610 (and probably earlier Garmin StreetPilot devices which had Garmin proprietary memory cards) There also was a time when you could purchase only specific regions of the U.S. or the entire U.S. Memory was relatively expensive then as was the software unlock code for the U.S.
Later Garmin units have all the detail maps preinstalled on the GPS unit so you don't need the MapSource software to install maps. I just bought a Nuvi 360 for my wife and it did not come with the MapSource software. The unlock codes for the detail maps that are installed on newer units are more akin to a software license serial number, from my perspective.
You should consider registering your Nav lll with Garmin. Then download the Garmin Web updater software to you PC so you can make sure your GPS device firmware, USB drivers, voices, etc. are the most current.
Visit the Garmin support site for info on how to register.