Changing MAC addresses on Windows 2000 and XP

This is depending on the type of Network Interface Card (NIC) you have. If you have a card that doesn't support Clone MAC address, then you have to go to second method.

• Go to Start » Settings » Control Panel and double click on Network and Dial-up Connections.
• Right click on the NIC you want to change the MAC address and click on properties.
• Under "General" tab, click on the "Configure" button Click on "Advanced" tab.
• Under "Property section", you should see an item called "Network
  
• Address" or "Locally Administered Address", click on it.
• On the right side, under "Value", type in the New MAC address you want to assign to your NIC. Usually this value is entered without the "-" between the MAC address numbers.
• Goto command prompt and type in "ipconfig /all" or "net config rdr" to verify the changes. If the changes are not materialized, then use the second method.

If successful, reboot your systems.