Changing MAC Address in Windows 7 & Vista

The MAC Address of Network Devices in Windows 7 & Vista can be changed by making a simple change to the registry. A possible step-wise approach to accomplish this is presented below.

• Open Windows Registry Editor.
• Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class from the tree view on the left hand side.
• Open Command Prompt.
• Type getmac in Command Prompt and press enter to get the MAC Address of Network Interfaces on your computer. You will see the MAC Addresses of all Network Interfaces you have on your computer including virtual ones.
• Copy the GUID in Transport Name part of the device whose MAC Address you wish to change. The transport name is like \Device\Tcip_{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX} where the GUID is the part highlighted in yellow.
  Note: The transport name will not be displayed for network devices which are disabled. So if you have a wireless network device and have it switched off you then will not be able to see the transport name of the wireless network device.
• Go back to the registry editor and press Ctrl+F to display the search window.
• Paste the GUID you found into the text box in the search window.
• Next untick both Keys and Values under LookAt and tick Data.
• Click Find Next to search the registry.
• The Registry Editor will automatically take you to a Key similar to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\XXXXXXXX-XXXX-XXXX-XXXXXXXX\00## and a String Value with the name NetCfgInstanceId would be highlighted on the right hand side. This String Value would contain your GUID.
  Note: You may have to search a couple of times before you are able to find this key.
• Right click on an empty space on the right hand pane in the Registry Editor windows and select New -> String Value. 
• Type NetworkAddress for the name of this new String Value.
• Double Click the new String Value you just created i.e. NetworkAddress and enter the new MAC Address you want for the interface. The MAC address should be in hexadecimal without any hyphens and should be exactly 12 characters long. Example: 00AA22BB44CC
• Close the Registry Editor and restart your network device for the change to take affect.
• To restart you network device you can either restart your computer or disable and re-enable your network device (using the Control Panel -> Network and Sharing Center).
• To check whether the MAC Address of the device has changed you can open Command Prompt and enter getmac.