Changing MAC Address of the Computer -
Changing MAC Address of the Computer
MAC Address of Computer
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.

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..!
See Also
   MAC Address Scanner: Free Tool to Scan & Discover MAC Address of all Network Systems
   Ne tShare Monitor: Watch your shares from intruders. 
   Proc Net Monitor: Tool to monitor network activity of process.
   Recover Windows password in seconds using Rainbow crack. 
   Proc Heap Viewer: Enumerate process heaps on Windows.