Verify USB driver installation in Windows
Once the GMC-300E PLUS is connected to a computer, from the device manger, you should
see which COM port is assigned to the GMC-300E Plus. See the example below. Windows
assigned COM3 to the GMC-300E PLUS unit in this example.
For the Data Viewer or the data logger software, selecting COM3 will establish the connection
to the GMC-300E PLUS Geiger counter for the above example