Cannot assign IP address to a NIC after a physical to virtual or Virtual to Virtual conversion because a duplicate IP exists

You May Get an error  " The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter" After the conversion of a Physical Server to VM or VM to VM


Solution: A

To resolve this issue, follow these steps inside the guest operating system:

Click Start > Programs > Accessories > Command Prompt. (Type the following command and press Enter:)

set devmgr_show_nonpresent_devices=1

Type the following command , and press Enter:

start devmgmt.msc

Click View > Show hidden devices
Expand Network adapters. The old physical network cards are grayed out. Right-click on these NICs and click Uninstall. Once all of the grayed out NICs are uninstalled, assign the IP address to the virtual NIC.

Solution : B

Another method of resolving this problem is to use the DevCon utility. This is a command-line utility that acts as an             alternative to Device Manager. When you use DevCon, you can enable, utility disable, restart, update, remove, and            query individual devices or groups of devices.
Download the DevCon tool from Microsoft Knowledge Base article 311272. (Download Devcon Utility from the below link )
http://support.microsoft.com/kb/311272
Unpack the 32 bit or 64 bit DevCon tool binary to a local folder.
Click Start > Run, type cmd, and press Enter. Type CD:\path_to_binaries to navigate to the devcon.exe is located.Use this syntax to find installed network adapters:

devcon findall *net*            
or
devcon listclass net

Note: In the output of the previous commands, there is a line for the ghosted network adapter that is similar to PCI\.Run this command to remove the adapter:
devcon remove @device\name 
For example, devcon remove "@PCI\VEN_14E4&DEV_1600&SUBSYS_01C21028&REV_02\4&378EDFA4&0&00E2" . 
Note: IDs that include an ampersand character (&) must be enclosed in quotation marks as seen in the example.
Reboot the system and you no longer see the ghost network adapters.