JSI Tip 2842. The IP Address you have entered is already assigned?

When you enter the IP Address on a NIC, you receive:

   The IP address  you have entered for this network   adapter is already assigned to another adapter .    is hidden from the network and Dial-up Connections   folder because it is not physically in the computer or is a legacy adapter   that is not working. If the same address is assigned to both adapters and   they become active, only one of them will use this address. This may result   in incorrect system configuration. Do you want to enter a different IP   address for this adapter in the list of IP addresses in the advanced dialog box?

Where is the IP address that you are trying to set and is the name of the network adapter that is present in the registry but hidden in Device Manager.

If you press Yes, you can change the IP Address. If you press No, your NIC and the ghosted NIC have the same address. This is not normally a problem as the driver for the ghosted NIC is disabled.

This problem is genrally caused by moving the NIC to a different PCI slot.

To fix the problem:

1. Open a CMD prompt.

2. Type:

    set devmgr_show_nonpresent_devices=1

3. Type:

    Start DEVMGMT.MSC

4. Press View and Show Hidden Devices.

5. Expand the Network Adapters tree.

6. Right-click the ghosted NIC and press Uninstall.