Thanks I will add it to Tutorial index.
There are pieces of this "high level" how to in many places, and if you get a new computer one relatively quick way to transfer your maps is as follows (as opposed to reinstalling maps).
These directions were written for 64bit installation in Windows 10, which fortunately is the same garmin structure as Windows 7. 32 bit machines have a slightly different registry path (no \wow6432node\) described elsewhere in these tutorials.
After installing basecamp in new computer, any .gmap map directories can be copied across to \program files (x86)\garmin\basecamp\maps and read by basecamp.
Any other maps that do not have .gmap directories, require an export of the LOCAL MACHINE\SOFTWARE\Wow6432node\garmin\mapsource\Families registry keys from the old computer, with the new paths corrected and imported in the new computer.
If editing the keys in notepad, note that the key "data" directory paths require \\.....
Old computer example (notepad)-
"Loc"="C:\\Program Files (x86)\\Garmin\\BaseCamp\\Maps\\TopoUSVer5\\"
"Bmap"="C:\\Program Files (x86)\\Garmin\\BaseCamp\\Maps\\TopoUSVer5\\mapset.img"
"Tdb"="C:\\Program Files (x86)\\Garmin\\BaseCamp\\Maps\\TopoUSVer5\\mapset.tdb"
Then, if mapsource is installed (use the .msi to install) (after basecamp preferred), it might only see the maps in the families registry keys. It may not see the .gmap maps, since mapsource uses \program data\garmin\maps path as the default, and basecamp defaults to \program files (x86)\ path. To allow mapsource to see the .gmap maps, put shortcuts in the mapsource map directory and mapsource will then show the maps.....
Thought I would write this down, since it is always a re-learning experience after several years time goes by