How to Find Your Ethernet Address

In Windows Vista
1) Go to the Start menu.
2) Type cmd where it says Start Search in the lower left and press Enter
3) Type ipconfig /all in the black window that appears.
3) Look for Ethernet adapter Local Area Connection, then Physical Address in the text that is returned.
 
In Windows NT/2000/XP
1) Go to the Start menu, choose run.
2) Type in command and press ok.
3) A DOS window will open up. At the DOS prompt, type "ipconfig /all" and press enter.
4) Look under the Ethernet adapter information for the physical address. This is the ethernet address. It will begin with a zero and have 12 characters separated by dashes.
 
On a Mac OS 10.2
1)  Open the System Preferences and choose Network.
2)  Choose "Built-in Ethernet" from the "Show" drop down menu.  You will find the Ethernet address in the TCP/IP tab.
 
On a Mac OS 10.3 +
1) Open System Preferences
2) Open Network
3) Double-click the built-in ethernet entry to see the settings.
4) Click on the Ethernet tab.
5) You should see the ethernet address there. It will be 12 characters consisting of the numbers 0-9 and the letters a-f