Hack 46 Remove Orphaned Network Cards

Moving a network adapter card to a new PCI slot in Windows 2000/XP can sometimes cause unexpected results .

If you swap out a network interface card (NIC) or move it into a different PCI slot but neglect to run the PnP Hardware Removal wizard or use Device Manager to do so, you might end up with an orphaned NIC. When you perform your hardware change with the card, power up the system, and log into Windows 2000/XP, the hardware wizard might display a message telling you that it detected a change. When you go to configure the network card's TCP/IP settings and try to save them, it will say "Hey, those settings are associated with this network card. Are you sure you want to use them for this one?" Then you'll realize the error you made. So, how do you remove the configuration settings for that orphaned NIC?

To remove your orphaned NIC, you first need to know the Registry keys associated with it. This is the first such key:

 HKLM\Software\Microsoft\WindowsNT\CurrentVersion\NetworkCards 

You might see one or more subkeys numerically incremented. Selecting the subkey shows you two values:

Description

This contains the displayed description of the network card.

ServiceName

This is the GUID of the network card that is referenced in the Services section of HKLM where the TCP/IP configuration information is maintained , and also under the Enum\PCI section where the configuration parameters of the network card are maintained.

This is another important key:

 HKLM\System\CurrentControlSet\Services\{   GUID   } 

Within this key, the Parameters\Tcpip subkey contains the TCP/IP configuration settings for the network card, including the DHCP server IP address, the lease information (if you're using DHCP), the subnet mask, and so on.

Here is the third key:

 HKLM\System\CurrentControlSet\Services\{   ServiceName of Network Card   } 

This key represents certain driver parameters related to error control, path to the driver file, and so on. The Enum subkey also points to the PnP Instance ID of the device, if you want a shortcut to where in the HKLM\System\Enum section of the Registry the device is maintained.

This is the fourth key:

 HKLM\System\CurrentControlSet\Control\Network\{   GUID   } 

This key stores all information related to devices that serve as communications media to transmit/receive data between devices, such as network cards, infrared ports, and so on. It also contains configuration information for the key Microsoft Network services, such as File & Printer Sharing, QoS, and so on. Each device/adapter has a GUID subkey under this section of the Registry, where you can find the information related to that device. For the network cards, find the appropriate GUID and under this fourth key is the Connection subkey that maintains information related to PnP and the name of the connection (as you see when you go to Start Settings Network & Dialup Connections). The PnpInstanceID value is what we are interested in, because it points to a section of the Registry that maintains configuration information for Plug and Play devices.

Finally, this is the last key you need to know about:

 HKLM\Enum\PCI\{   PnPInstanceID   } 

This key and its subkeys maintain information specific to the card, such as the PCI Bus it is installed in, driver information, and so forth.

Once you find all this information, you can delete those keys related to the card that was once there in the system. Then, you will no longer have to worry about issues of conflicting TCP/IP information between the old card and the new one or orphaned information that may or may not cause conflicts later on.

Use this hack at your own riskmaking any changes in the Registry could have dire consequences. Make a backup first and get comfortable with what you are modifying/removing before proceeding with the recommended steps in this hack.

Matt Goedtel