The default baud rate is 4800 and there is no need to change the baud rate settings in the Device Manager to 4800. Just leave it as it is. In the SiRFDemo, you just have to manually change the baud rate to 4800. Similarly, you have to select 4800 when you switched the protocol to NMEA mode. As mentioned earlier, the default value for the baud rate is 4800.