Is it asking you to set the navigation path at startup?
If yes that means it currently cannot find the navigation software when you press the Navigation icon.
If you have put new software on it make sure folder structure is the same as it was before, and the .exe file is the named same as the original.
If that does not work, or the software's location has been changed by you (was previously on device's storage, now on MicroSD card etc.), then on the 2nd page of icons when it starts up there is an icon called Navi Path, tap that and there you can set the path to the .exe of the software.
If that's not what you mean then I don't understand your post correctly, no offence intended but it's a little hard to understand.