When you trying to set the IP address on a network adapter, you may receive the following error message:
The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of 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?
A network adapter with the same IP address is in the registry but is hidden in Device Manager. This can occur when you move a network card from one PCI slot to another PCI slot.
1. Click Start, click Run, type cmd.exe, and then press ENTER.
2. Type set devmgr_show_nonpresent_devices=1, and then press ENTER.
3. Type Start DEVMGMT.MSC, and then press ENTER.
4. Click View, and then click Show Hidden Devices.
5. Expand the Network Adapters tree.
6. Right-click the dimmed network adapter, and then click Uninstall.
This problem happens to my colleague whereby no internet connectivity to looking for solution. What really happen is that when the technician came and change the MOBO, maybe he had change the location of the PCI network slot.