When using Windows based virtual machines, especially those deployed from templates, you may occasionally receive the notification “The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter”
This issue occurs if a network adapter with the same IP address is in the Windows registry but is hidden in the Device Manager (My Computer > Properties > Hardware > Device Manager). This hidden adapter is called a ghosted network adapte
This can easily be removed by opening the command prompt with administrative access and typing the following command:
This will start the Device Manager. It is important to start the Device Manager from the same command prompt, since it will lose the setting to show the non present devices. If you open the Device Manager from the Control panel, the hidden devices will not show.
When the Device Manager loads, from the File menu, expand the View and select the Show Hidden Devices option. This will enable and show any old un-used devices in the window. From here, expand the Network Adapters node and you can right click on the devices which are extra and delete them accordingly.
I have seen this issue on both VMware created machines and Hyper-V