Just a quick note for those struggling to update maps on their GPS device: try using Windows XP.
I don't want to share this on a troubleshooting forum because I don't want to get jumped on by the techno-geeks for providing such a primitive solution.
I bought the Nuvi 2300 widescreen in mid 2011. It's a beautiful device that has every speed camera and speed limit on the roads down to the metre. Problem is cameras move around and speed limits can change if there's construction going on or if the government feels a bit bored. You need to update your maps at least every two months. Now, Windows 7 was launched well before this Garmin came out, but for some reason I couldn't install the Garmin Map Updater software which is compulsory if you are to update the maps. I kept getting error messages on my Windows 7 64 bit machine when I tried to install it.
I swear it occurred to me while I was meditating to try plugging my Garmin into my old Windows XP machine and give it one more try. The prompts on the Garmin site led me to first install the Garmin Communicator then Garmin Map Updater. Everything just worked.
But I'm complicating things: if you're struggling to update maps, try using a Windows XP machine and the prompts on the Garmin site (www.mygarmin.com) will show you the rest. If I can help just a handful of people with this solution then this post would have been worthwhile.