The IP address xxx.xxx.xxx.xxx you have entered for this network adopter is already assigned to another device....

How to find a hidden, lost, missing, or removed LAN (NIC) card?

Go to Start > Run > type cmd > and type the following command.

set devmgr_show_nonpresent_devices=1

Then

Go to Start > Run > cmd and type the following command.

devmgt.msc

in device manager show the Network Adopters
and uninstall the hidden network adopters.

will solved your issue

Or simply use this Tool

For Windows8 or Windows server 2012

For Win XP, Win 7, Win server 2003 and 2008

Thanks,