It seems for some reason the installation of the virtual com port fails. I suggest you search Windows Event Log, part "Application", for records with source "1274Serial" and read the error text for them. The actual error might be in the last part of the text. The "System" log might also show something. You might try to uninstall the ports first, clear the logs, and then reattempt installation. That way it's easier to see what might be in there caused by the failing installation.