John wrote:

Thanks for the detailed explanation and advice. My friend didn't want
to go through all the steps; he's kinda convinced (as am I and as is
the tech support guy at the company he bought from) that it's a case
of dead hardware.

He was ready to RMA the box but they offered instead to send him a new
mobo, which would be faster and cheaper than shipping the whole
computer back. I told him to go ahead and I'll give him a hand
swapping the board.

I'm pretty sure that we should be able to do this without reinstalling
any software. That is, we can shut it down, swap the board, then turn
it on and Windows and all its drivers and such will never know the
difference and will just boot up and run.

Am I right about this? Are there any gotchas that I have to worry
about? (I'm assuming they will send a same-rev board, which I'll
check before we start.)

Reply-to address is real

John

Windows activation keeps track of hardware changes. When you change
the motherboard, it changes the NIC MAC address.

This ancient article describes how it works.

http://aumha.org/win5/a/wpa.htm

It would really depend on how many perceived changes
have happened to date, as to what it would think
about the new motherboard. If only the motherboard NIC MAC
changed, maybe it would simply work :-)

Paul