What files to back up

I have about 11 garmin units registered, friends and used ones I have sold. I keep them updated by listing all files with each serial number on my computer. When I update, I put the files on the particular units that the updates apply to, then hook up and update the unit.

This keeps everything handy and organized, by the way, I am retired.

I back up every file & folder on my GPS to my PC hard drive. If something goes wrong, you won't know what you will need to restore until it happens.

The size of the other files compared to the map image are tiny, so there is no reason not to back them up.

The map file alone is 1.2GB. All files total 1.5GB, only 300MB more.

These numbers are from my 660 so YMMV on different models.

I agree that you should keep a backup copy of all files on your Nuvi as a safeguard against a disastrous map or firmware update but if you only want to save the current City Navigator map file before updating the maps then the file your looking for is called gmapprom.img