here is some info I found on changing the mac address of the actual card. Spoofing the mac address is a lot easier than changing the hard coded address of the nic card.
[edit] Changing addresses
Although physical MAC addresses are permanent by design, several mechanisms allow modification, or "
Spoofing_attack", of the MAC address that is reported by the operating system. This can be useful for
Privacy reasons, for instance when connecting to a
Wi-Fi hotspot, or to ensure interoperability. Some
Internet_service_provider bind their service to a specific MAC address; if the user then changes their network card or intends to install a
Router, the service won't work anymore. Changing the MAC address of the new interface will usually solve the problem. However, this action is generally frowned upon and if the service provider is able to detect that a MAC address is spoofed and prohibits spoofed MAC addresses, this method will not work. Similarly, some software licenses are bound to a specific MAC address. Software-based changes to the MAC address simply modify registry entries and are not permanent; after a reboot, the MAC address will revert to the MAC address physically stored in the card.
A hardware-based change to the MAC address, on the other hand, is permanent because it erases the MAC address physically stored in the card's EEPROM and overwrites it with a desired MAC address. Making this hardware-based modification is tricky, however, as it requires the user to operate
Desoldering equipment and an
EEPROM Programmer (hardware). A link below outlines the process involved in making a hardware-based change to the MAC address. Due to the difficulty involved, the risk of destroying the network card, and the risk of sustaining serious burns, this method IS NOT ADVISED.
As a MAC address can be changed, it can be unwise to rely on this as a single method of
Authentication. IEEE
802.1x is an emerging standard better suited to authenticating devices at a low level
more details can be found here:
MAC_address