Thank you for your quick reply. When I connect the dongle to the computer, I get a message that says "The last USB device you connected to this computer malfunctioned, and Windows does not recognize it."
So I ignore that message and log into the store. Once there, I click on "Register a new interface."
Then I get a popup that says, "Please disconnect then reconnect the usb dmx interface."
So I do.
Then I click on register again, and it tells me to please disconnect...
I'm thinking at this point that I have a defective interface.