NavCoder changes the programming inside the nav unit. It doesn't alter the OS. You need to change the programming 9coding) to restore the languages and settings you want.

You need a hardware interface - an ibus interface - which you must either buy or build

In the NavCoder zip file there is a schematic for a simple ibus interface, which is the one I use.

And you also need a laptop with a com port.

Jochen