USB Not Supported in WinLoad Software
It is not possible to load firmware onto the GPS receiver using the USB port with the WinLoad software. Part of the problem here is that the GPS receiver's power must be disconnected before the "Write Flash" button is pressed within the WinLoad software. Disconnecting the power to the GPS receiver, however, causes the USB driver to unload on your PC, and so WinLoad can no longer access the virtual comport associated with the USB port on the GPS receiver. Please use a standard serial port (RS-232 or RS-422) to load the firmware onto your NovAtel GPS receiver.