Maps v3.06 and later allow the downloading of map data directly to the device via Wi-Fi (WLAN) connection. No PC is needed in this case for transferring the map data.
Map data can be downloaded via Wi-Fi connection in the following way:
After the map data has been downloaded, the maps on your phone are shown on the Update or Map loader page. You can check with Check for updates command if there's any updates available for your map data.
If your device isn't recognized by PC when plugging via USB cable, try the following actions to recover:
If the above actions don't help, reset the device back to factory settings.
Check also that you have the latest device software version installed in your mobile device.