Did some more research and it seems that this is the result of a blank line in the actual values of your default gateway on that particular adapter within the registry.
You can track it down if you'd like here, but only if you are comfortable editing the windows registry as improper editing of the registry can result in serious problems overall to your computer so travel at your own risk.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameter\Interfaces
All your adapters will be located under that key and the problem adapter can be located by it's IPAdress value in the right pane once you've selected it in the left pane.
Once you've identified the correct problem adapter, double click the "DefaultGateway" value in the right pane and look at the Value data: box and if there is a blank value at the top followed by correct value(s) just edit out the blank line.
If you are reluctant to do this just rebuild the TCP/IP stack and that will take care of it for you.
Follow the
manual instructions listed here (since it's actually for Vista and below I'm not sure if the automatic "Fix It" will work for you but I know the manual instructions work for Windows 7)
Good luck and keep us posted.
Regards
Randy