One of the most frequent issues we see in Tech Support with using the Dynon Support Program is getting the DRIVER for the USB - Serial Adapter working correctly in Windows. Before the Dynon Support Program can communicate with the Dynon unit, the driver has to be working so the data can flow back and forth.
Sometimes the driver just won't install correctly in Windows. Other times, the driver gets set up for a COM port higher than 10 (which the Dynon Support Program can't deal with). Etc.
In Windows Control Panel, check Device Manager. Under Ports (COM & LPT), you should see your USB - Serial Adapter listed (with no red exclamation point indicating a problem). Dynon's USB - Serial Adapter should display as:
Prolific USB-to-Serial Comm Port (and display what COM port it's assigned).