Sorry to resurrect this post, but there is a way to spoof a MAC address in Win2k/XP. Let's see if I can remember: (BACK UP YOUR REGISTRY FIRST!!!)
Open cmd and type ipconfig /all
Next to DESCRIPTION on the above's output, is the name of your NIC. Under PHYSICAL ADDRESS is your MAC address.
Open rgedt32 (not regedit on purpose)
go to HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>Control>Class>{4D36E972-E325-11CE-BFC1-08002bE10318
^
(O god :shock:)
There will be a bunch of subkeys with numbers like 0000, 0001, 0002, etc. Click on each one and there is a entry "DriverDesc". Find the one with the name of your NIC (mine is 0008) and add a value called NetworkAddress, Data Type=Reg_SZ.
Edit the string by double-clicking it and add the new MAC address that you want to have.(Don't enter a "-", in other words, 00-00-00-00-00-00 would be entered as 000000000000)
Go to Network Connections and right-click the NIC you changed and select disable. Do the same again but enable it. If you cannot enable/disable, then you must reboot.
Go back to cmd ipconfig /all and verify the address was changed.
To restore the original manufacturer address, just delete the value you made earlier.