How to Change the MAC Address of A Computer

MAC Address of Computer:

A Media Access Control Address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for  most IEEE 802 network technologies, including Ethernet.

Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.

MAC addresses are most often assigned by the manufacturer of a Network Interface Controller (NIC) and are stored in its hardware.

Any packet sent to remote system on the network contains MAC address and IP address of your computer. Many of us are still under the impression that IP address can be changed, but MAC address is fixed and cannot be changed unless network card is replaced. Though we cannot change the MAC address of the network card, we can certainly change it in the operating system.

Here are the steps to change the MAC address on various operating systems.
Changing MAC Address on Linux:

On Linux platform you can just use 'ifconfig' command to set the new MAC address as shown below.
ifconfig eth1 down
ifconfig eth1 hw ether 11:12:13:14:15:16
ifconfig eth1 up

Changing MAC Address on Windows:

In windows you can use a console tool called 'etherchange' to change the MAC address. When you run this tool, it will show you all available network interfaces and then you can select particular interface to change its MAC address. You can just disable and enable that network adapter for changes to take effect. Once you have finished playing your game, you can run this tool again to restore the MAC address back to original. It is basically achieved through a following registry hack. Open up your registry editor and move to the following location.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\
{4D36E972-E325-11CE-BFC1-08002bE10318}
The above key has many subkeys with names such as 0000, 0001, 0002 etc. Each of these keys have a "DriverDesc" value on the right side which contains the description of the network card. You have to go through each one of these entries until you find out the one with the same description as your current network interface. Once you have found it, just create following string value to set new MAC address (in hexadecimal).
NetworkAddress REG_SZ 111213141516
Once you have changed it, disable & re-enable the network card for changes to take effect. Then use the command 'ipconfig  /all' to verify new MAC address. To set that network interface back to the original address, just delete the above value from registry.
Now you know what can be changed and what not..!