I just migrated to a new, Windows 8.1 PC. Just installed HRD (HamradioDeluxe).

I have a Prolific USB to Serial converter. Worked always fine on Win XP. Installed also fine under 8.1.

When I now open HRD, the Connect menu shows indeed the USB serial port as COM3 (next to COM1). However, in the connect menu I can only select COM1 in the pull down menu for the radio connection (not COM3).

For sure someone has been here before :-) Looking forward!

Henk - PA3GUO