WinXP New Re-Install Question.

I've activated WinXP on another PC, and about to install it in a new PC. I understand that the NIC has the most weight in the hardware checksum that forms a part of the activation. Should I transfer the NIC from the existing PC to the new one, to avoid errors when re-activating with MS? If so, I would imagine that the old PC will not work with a new NIC, given the existing checksum stored for comparison on boot-up. Anyone done this and can suggest if reloacting the original NIC is necessary?Thanks,Bruce.