Hi Steve Thanks for your thoughts on this problem. My radio is plugged direct into my computer (USB3); maybe I wasn’t clear enough in my description of the problem, sorry about that. The radio display is stable when I run XP 10 which tells me that XP 10 and radio are connected. Let’s take “NAV 1” as an example; when I go to change frequency, let’s say I want to change to 111.5 ILS, as I rotate the knob the digits are trying to change as in they just flicker (they do not switch off) both on the radio unit and the radio on the panel in XP 10; I have the same problem trying to change the COM also. I hope this gives you more of an idea as to my problem. Thanks ANC23