MAC address of computers

[oldexpat]

Is it possible to change a MAC address of a computer? Also what is the MAC address comprised of? If you change your hard drive do you create a new MAC address?

[squarebear]

1) No
2) A series of numbers and letters like 00-AE-HB-7A-81
3) No

Why do you want to change your MAC address?

[squarebear]

Actually, ignore me. There is some software that will allow you to change it.
http://www.technitium.com/tmac/index.html

[ChuckFickens]

1) yes, it's not something you can do easily from windows without extra software.
2) a 6 groups of 2 hexadecimal numbers
3) no, the mac address is on your network card, not the hard drive

Why would you want to change it, they are not used at all on the internet, they only get used on a local network and the information is not passed by routers.

[oldexpat]

Thanks for the answers. Do routers keep a register of all the MAC addresses that it connected to?