How do I put OSM maps on my MapSource?

I downloaded built OSM maps on to my Nuvi 500. Now I want to put other maps on my PC. I downloaded this file: “osm_generic_windows.exe” 01-Sep-2012 23:57 1.0G Map installer for BaseCamp/MapSource on the Windows platform. I downloaded it to my desktop and ran it. After it installed,I opened Mapsource and had no maps. Under Map Product Information it shows OSM generic routable and Installed Location C:\Garmin\Maps\OSM generic routable. Then I opened Computer\C\Garmin. I found a “Maps” folder containing “OSM generic routable” modified 9/1/2012 and “OSM World Routable” modified 12/22/2011. Also under Computer\C\Garmin I found a folder named “OSM World Routable” modified 12/22/2011. Inside this folder are 16 .img files. I think I have followed install directions correctly. Any ideas what I have done wrong?

Did you press CTRL+G 2x in Mapsource.
Have you read ?

Yes,I tried their suggestions.But they didn’t work.

I think the problem is caused by the older OSM World Routable map. Try to completely remove this old version (from the registry and the harddisk) then install the newer generic routable map.