The MAC address is unique
to your network card and takes the form of 12 characters
(in 6 sets of 2), e.g. aa:aa:aa:aa:aa:aa.
Note that the first character
is usually 0 for network cards and 4 for modems.
Windows 95/98/ME
Select Start > Run, type winipcfg in the box, then click
OK. Select your network card from the drop-down box and the MAC address
will be given in the box labeled Adapter Address.
Windows NT/2000/XP
Select Start > Run, type command and press OK. At the
Command Prompt, type ipconfig /all, and press Enter. The
MAC address will be given as the Physical Address.
Macintosh OS9 and less
Select the Apple Menu > Control Panels > TCP/IP > Select the
INFO button (If the INFO button does not appear, select the EDIT menu
> User Mode > Advanced); The MAC address will be given in the
next window.
Macintosh OSX
Go to System Preferences, click on NETWORK and select your network card.
The MAC address will be in the lower left corner of the window.
Linux/Solaris/SunOS
Type ifconfig -a as root in a shell. The MAC address will
be given as HWaddr.