Most of the successful USB to serial cable users are using the FTDI chip set. Unfortunately you will have to work with FTDI to resolve any issues with your PC install. Because you are doing a dual boot thing are you sure something doesn’t need to allow access to the serial port hardware? I seem to remember reading something like that recently.
Have you tried the simple short pin 2 and 3 “loopback” test? This will tell you if the thing is at least sending and receiving data. Short pins 2 and 3 on the DB9 end of the cable and type in a terminal window connected to the port. If you see the characters it’s at least working at some level.