I have downloaded and installed the Garmin software for my computer and the map I downloaded shows in the drop down list but it doesn't show in the display window. I opened the global map that was installed with Garmin but the WV trails map won't. I have even tried reinstalling the map.
Do I need to do something special?
Any help will be much appreciated.
I would help if you told us which map. Is this it? https://www.gpsfiledepot.com/maps/view/500/
That is a transparent overlay map. In other words, it just shows trails and points of interest - lines and dots with no background. So unless you have zoomed in on a specific trail, you will probably see nothing in Basecamp.
This type of map is only useful on the GPS itself. On the GPS, you would enable another map (such at a topo) at the same time as the trail map. The trails would then be added to the topo. You can't do this in Basecamp, because Basecamp will only show one map at a time.