Which version do you have? 12.1.10, 12.1.0, or some older? Did you downloaded OSM maps? By "wont open" you mean that the program does not even start or you see splash screen but then it disappears? There should be a hint in navigator.log.txt file (I guess C:\Users\<user>\AppData\Roaming\Navigator\12.1\ by default hidden folder). regards Martin p.s. the program should be the same and should work with free maps ...