Installing maps onto Garmin Basecamp

JamesB
JamesB Posts: 1,184
edited February 2013 in MTB general
I`ve downloaded a OSM map (UK with contours), unzipped it, downloaded TKmap too Both are in c:Garmin/ folder and want to install new map.
BUT the Map Install comamnd on Basecamp is inactive (ie grey not black). I`ve previously successfully installed OSM MTB maps but cannot get this new one to install at all :(:(...

any thoughts and help most welcome :)