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Change the MAC address of a network adapter

Affected products

  • Microsoft Windows 2000
  • Microsoft Windows 2003
  • Microsoft Windows XP


This articles explains how to change the MAC address of a network adapter.

More information

The MAC address uniquely identifies the network card within the current network segment. It consists of a vendor id that is unique among all network vendors, and a relative id that is unique to the vendor.
The address is hard-coded onto the network adapter. But since most of the drivers were deleveloped with the Windows Driver Development kit, the MAC adress is read from the Windows registry, when the card is initialized.


  1. Note the description and current MAC address of the card you want to modify. To do this, open a command prompt and type the following:
    ipconfig /all
  2. The description of the card is in the field "Description", whereas the MAC address can be found at the field "Physical address".
  3. Start the registry editor (regedt32 under Windows 2000, regedit under Windows XP and Windows 2003) and open the node
    When you expand this node, you will find several subnodes, each representing one of your network adapters.
  4. Find the node which contains the field "Description" in the right pane that matches the description of the network adapter you want to change.
  5. On the node with the network adapter to change, check whether there is an entry named "NetworkAddress" (without the quotation marks, of course). If there is such an entry, check if the entry type is "REG_SZ". If not, delete the entry and recreate it with the appropriate type. If the entry does not yet exist, create one.
  6. Double click the entry "NetworkAddress" and enter the new network address. Note that the new network address should have exactly twelve digits.
  7. Once you entered the new network address, the network adapter has to be restarted. To do this, open the control panel and then "Network and Dialup connections". Right click the network connection you have just modified, and then click disable. After the device has been disabled, right-click the connection again and click Enable.
  8. Open a command prompt, and type
    ipconfig /all
    to check, whether the new MAC address has been changed.
    If the displayed physical address is still the same, your network card is probably incapable of changing this setting.

Posted by Henning Krause on Friday, December 31, 2004 1:14 PM, last modified on Monday, November 22, 2010 10:43 AM
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