IP address assigned to non-existent adapter

Solution 1:

WARNING

Insert usual registry editing warning here - in short backup your system before you mess with the registry and don't mess with it if you're not comfortable doing so.

Now that that's out of the way...

Search the following registry location for the IP address:

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces

If you find the IP address in question under a GUID key (ie {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}), then there should be a correlating key under:

HKLM\SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}\####

Which has a sub value named "NetCfgInstanceId" with the same GUID you identified in your first search.

You will also find a reference to that GUID under:

HKLM\SYSTEM\CurrentControlSet\Control\Network\{4d36e972-e325-11ce-bfc1-08002be10318}

Which has a subkey\value of Connection\Name that contains the name of the network connection as you saw it in the Network devices view from control panel (ie. "Local Area Network").

I haven't done this in Windows 10 yet, but in previous versions of Windows (7 and 2008 R2) I've deleted all three of the keys that reference the NIC/IP (do not delete the parent keys that contain ALL the NICs on the system - just the key for the specific NIC/IP you're having problems with) in order to get rid of problems like the one you're describing. At the very least you should export the keys first so that you can add them back as needed.

And, I don't remember, but I wouldn't be surprised if you have to reboot before the changes will be effective.

FYI: This same method can be used when Windows says the name you're trying to assign to your network connection/NIC is in use and you can't see it. (The name will be under HKLM\SYSTEM\CurrentControlSet\Control\Network\{4d36e972-e325-11ce-bfc1-08002be10318}\<GUID>\Connection\Name)