Cabling
In rare instances this can be related to
a problem with the modem not responding appropriately. In
order to test this unplug the grey USB cable which connects
the modem to your computer. This should cause both lights to
go out on your modem as the power source has been
disconnected. Then replug the modem into the USB port on
your computer and wait until the modem lights both go solid
green before trying to reconnect.