If you are trying o to load an OSM map for use in your garmin then similar questions have been asked before "SomeoneElse"'s answer is the best one, see https://help.openstreetmap.org/questions/3785/osm-on-garmin you will probably need a memory card to put the map on, and that is safer than using the internal memory of your garmin. Once un-zipped and installed on the card and into the Nuvi look through the garmin device menus to select or deselect the map you want to use. I am guessing a bit as I don't have Nuvi 40 but that is how it works on Nuvi 1310t and Oregons.

Very If you are trying o load an OSM map then similar questions have been asked before "SomeoneElse"'s answer is the best one, see https://help.openstreetmap.org/questions/3785/osm-on-garmin you will probably need a memory card to put the map on, and that is safer than using the internal memory of your garmin. Once un-zipped and installed on the card and into the Nuvi look through the garmin device menus to select or deselect the map you want to use. I am guessing a bit as I don't have Nuvi 40 but that is how it works on Nuvi 1310t and Oregons.

Very similar questions have been asked before "SomeoneElse"'s answer is the best one, see https://help.openstreetmap.org/questions/3785/osm-on-garmin you will probably need a memory card to put the map on, and that is safer than using the internal memory of your garmin. Once un-zipped and installed on the card and into the Nuvi look through the garmin device menus to select or deselect the map you want to use. I am guessing a bit as I don't have Nuvi 40 but that is how it works on Nuvi 1310t and Oregons.