I have tried to download a free map from the website, but there is no link to do that,the list of available maps for navigatorfree is visible, but no link to upload any countries,
The concept for at least the Android version is, that you download and maintain maps from the map-manager within the app. There is no necessity to downoad and transfer them in two or more steps. I wonder, if this is different at the WinCE app on mobile Windows devices.
The windows setup utility as well provides an option to install maps directly to your mobile device (also there called PocketPC; quite old fashioned by the way ;-) ).
What you also can do, is via using the Navigator Setup Utility for Windows, to download map to your Windows pc and transfer them manually to your device.