How does the device come up in the Device manager? Is it present in the other devices section?
Please make sure the serial driver is installed.
Hi Richard, I have *exactly* the problem you describe here!.
It happened as well after trying to install a second com port using the instructions on the Superspeed Book. Even after reinstalling the USB Serial port as recommended by Madhu Sudhan, I cannot see any COM ports on device manager. I do see the "USB-Serial" devices however.
Did you manage to solve this problem?