You're using cgminer 3.2.1. It doesn't work with the UART driver (it's what makes it show up as a COM port). Use 3.1.1 and you should be fine.
If you want to use 3.2.1, you'll have to uninstall the UART driver. Rumor has it this doesn't work properly if you have it plugged into a USB 3.0 port. I haven't tried it yet, took too long for me to recover from trying 3.2.0.

M
Just hoping for a quick clarification: By USB 3.0 port do you mean on the computer or where the miner is physically connected. I guess what I'm wondering is if the miners being plugged into a USB 3.0 hub but the hub being plugged into a 2.0 port on the computer makes a difference or if any USB 3.0 connection in the chain is enough to mess it up.
I'm running on 3.1.1 right now, but would love to try 3.2.1 to see if it does reduce the number of HW errors as some have reported. But I don't want to generate unnecessary problems for myself if it is already known not to work.