How to change the MAC address of my system?
MAC (Media Access Control) address is a unique identifier assigned to network adapters or network interface cards (NICs) by the manufacturer for identification.
This is a permanent number which is embedded in the hardware of network adapters which can not be changed later. However, at the software level, i.e. in the operating system, it can be changed to whatever address you want.
How to change a MAC address in Windows XP
A program called Macshift, which is a free command-line MAC changing utility for Windows XP will let you change the MAC address of the network card at the software level. Changing the MAC address on your Windows system becomes an easy task with Macshift.
How to change a MAC address in MacOS
Follow the instructions mentioned on MAC address spoofing to change the MAC address in MAC OS.
How to change a MAC address in Linux
To change the MAC address in Linux OS, use the command 'ifconfig <interface> hw <class> <address>' (without quotes) or you can use GNU MAC Changer.