In order for a Windows App to be able to read the GPS data from a NMEA USB GPS Receiver, you'll need to convert the COM port to a "GPS Sensor".
Please download and install this application, which should be able to convert the COM Port into a GPS Sensor: https://www.dropbox.com/s/ee1r4kl09iimfdk/gps7s64.zip?dl=0
1. Extract all files & double click on gps7s64.exe file.
2. Select your COM port for NMEA source
3. Select 4800 baud rate
4. Click Install
5. Now you should see GPS data in the GPS Sensor Utility.
6. Leave this tool running and open up your Navigation App and see if you're able to get it to work.
If you're not able to get it working, then perhaps you can purchase the latest version of this software here: http://www.turboirc.com/gps7/
and click on "GPS Direct" and contact the GPS Direct developer for further assistance.
Let me know if you have any further questions. Thanks.