For the local machine:

1. Click Start
2. Click Run
3. Type cmd
4. Click OK
5. Type ipconfig /all
6. Press Enter
7. You will get something similar to the following:
8. The MAC address is the same as the Physical Address listed here.
   
   
   
   

For a Remote machine:

1. From any Windows XP Workstation:
2. Click Start
3. Click Run
4. Type cmd
5. Click OK
6. Type nbtstat –a WSID (the workstation id for the remote machine)
7. Press Enter
8. You will get something similar to the following: