If you have ever moved a virtual machine or replaced a NIC (Network Interface Card) on a physical server and wanted to keep the same IP Address, youip-address-already-assigned-to-another-adapter will have seen the following error:
You basically have three choices:Use a different IP – not likely what you want to do
Let Windows remove the old static – best answer
‘Uninstall’ the old NIC (which will remove the static residue)how-to-show-see-remove-old-hidden-network-adaptors
The problem with removing the old NIC is that it is hidden in Device Manager. Fortunately it takes about 3 seconds to un-hide devices in Device Manager:
Launch Device ManagerClick VIEW
Click SHOW HIDDEN DEVICES
Expand NETWORK ADAPTORS
Right click on the old/dead/hidden NIC’s and
UNINSTALL them
Normally I do this with Virtual Machines that are off line, but I just did one in Server 2012 with a live server and it worked with no interruption to my RDP session so I think ‘sall good.

Ref:
http://www.urtech.ca/2013/06/solved-how-to-remove-old-hidden-network-adaptors/