1. Go to Start > Control panel > Network and Internet connections , then right click on the that network connection whose network card’s MAC address you want to change and click Properties.
2. In the General tab, click on the Configure button.
3. Then click on the Advanced tab.
4.In the Property section, you have to see an option saying Network Address or Locally Administered Address. Select it and change the radio button to Value ( Not present means that your network card will use the default MAC address programmed by the manufacturer ).
6. Restart the computer.
7. To make sure that the change is successful go to command prompt ( Start > Run, type in cmd and click OK ) then type in ipconfig /all.
As you can see the above method is very convenient but not all network cards offer such an option. For example, Broadcom 440x 10/100 ( used in Dell Inspiron 1501 laptops ) does not allow to change its MAC address through the Properties window. In such cases the following method will solve the problem.
1. Go to Start > Run and type regedt32 in the box to start the registry editor.
2. Go to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318} and double click on it to expand the tree.
3. Now you can see the subkeys starting with 0000, then 0001, 0002, 0003, 0004 and so on. Each of them represents particular network adapter.
4. Go through each subkey and look for DriverDesc keyword, that matches the network card you want to change the MAC address.
5. Look for a string value named “NetworkAddress”, right click on it and select Modify. Then enter a new MAC address in its value data box. If the value “NetworkAddress” does not exist, then create one with right click on the subkey ( for example 0008 ), then select New > String Value, name the new value as NetworkAddress and repeat the above step.