The com port thing is right where I got my butt tied in a knot. From that point on, it's easy.
On my rig, you have to type in the com port, and it's picky about what case letter you use in the "COM", requiring that I use upper case, and there is no space between "COM" and the com port number. So in my case, depending on the USB port the cable is plugged in to, it will connect if I type in COM4, or possibly COM3. That's my laptop though. The bigger point is, on my laptop anyway, it goes out of it's way to mess with you in this regard. Proper context is important as is the space or no space between "com" and the com port number. You can't imagine the frustration it took for me to get though this total BS, but patience persisted, again....