In your picture you have garmindevice.xml inside but on kenwood garmindevice.xml is different compare tu nuvi.

Try this:

Turn off kenwood and discconect cable from laptop

turn on kenwood but don't start navigation

connect laptop and kenwood

start navigation and you will see prompt if you like connect to mass storage or to connect to work with webupdater.

p.s.
in mass storage mode, webupdater don't see your device only in webupdater mode you can update your unit with webupdater.