Impossible to connect my cube trought USB

For four days I’m trying to connect my cube to mission planner with the USB cable.
Michael_Oborne try to help me but it is a mess.
when I install driver, the cube appear like a serial port named : “ProfiCNC CUBE F4-FMU”
but the COM is impossible to open with any serial communication software.
I’ve open a topic to ardupilot forum

Please help.