Updating Horizon HDSM meter:

Download SatMeter HDSM.exe
Download latest settings/ *.HEX file 
Right click - run as administrator. (You may get a warning and have to click more info – run anyway) 
Click File - Load and load the file from where it was saved on your computer. Should say file successfully loaded.
Select ComPort to correct port or USB if using USB meter
Click Transfer. 
Done