I had no problem downloading my first (small) map. It displayed well in MapSource and then BaseCamp.
Then I downloaded a second (slightly larger) map and when I ran the .exe, an error indicated that the 'OSM generic routable is already installed. So I aborted the install.
I hunted for the folder where the first map was located - ‘C:\Program Files\Garmin\Maps\OSM generic routable’ - and renamed it to ‘OSM generic routable-01’. Again I got the error on running the .exe, but proceeded this time. The new map displayed correctly in MS.
I then attempted to inspect the new folder, expecting it to be ‘C:\Program Files\Garmin\Maps\OSM generic routable’ and move files from the ‘-01’ folder. But the expected folder did not exist, although MS displayed the second map.
I then found a new folder - ‘C:\Garmin\Maps\OSM generic routable’. Confused, I looked here and then installed JaVaWa GMTK, which I had downloaded recently but not installed.
I changed the product ID, but still unable to re-install the first map.
My intension is to add to my map collection as required, to keep the downloads to a minimum.
Using Windows XP: Any suggestions?