Connect your TomTom-PNA with your Computer and visit this page.

If nothing is found immediately while your TomTom is definitely connected to your Computer
(e.g. TomTom Home finds it or it is visible from your Desktop), then press search.

When you see your device's serial number, then the connection works. :)

After that you can either install or remove the project.

You need to have Java installed to be able to use this Applet!
In case you are using Java > 7.51 and the applet is not loaded and instead a
message pops up that talks about security, please see this for the workaround!
In case nothing works you can install the project by downloading
and unpacking this package onto your TomTom.