If you are really desperate & can’t find any other way to unlock GMAPSUPP.IMG (Garmin Map) locked map files, because software like GPSMapEdit can’t seem to be able to deal with locked map files, and its always end up with “WARNING: The map is locked. (NOTE: such maps are not supported by intention).”

Here’s how to unlock GMAPSUPP.IMG (Garmin Map) locked map files :

1. Download Garmin Unlocker (download link at the end of this post).
2. Create “MAP Locked” directory, then copy your IMG file into directory.
3. Write your map details in MapsetHeader.txt and MapName.txt file

-MapsetHeader.txt eg. “Garmin City Navigator© NT 2010.30″ without quotes (50 characters allowed)
-MapName.txt eg. “Europe (Unlocked)” without quotes (50 characters allowed)



4. Run “UNLOCK MAP DIRECTORY.EXE”
5. Now you have GMAPSUPP.IMG inside “MAP UnLocked” directory