. . but that was yesterday. I'm doing another tonight (fresh distro with SP2).
I can't easily get parts for 2-year old machines anymore, so yesterday I repaired one by replacing motherboard (new AM2 socket), video (PCI-16), memory (DDS-II) and CPU (Semperon 64).
On bootup Windows said "Hardware changed, need to activate within 3 days". First attempt didn't go because no network driver. When I installed the driver and rebooted it wouldn't let me log in without activating - so much for that 3 days.
Fortunately there was a DHCP server on my network so it was able to contact Microsoft and get an activation key before log-in.
I'd installed from a SP1a distro (what the client had), got all the patches and updates, then went for SP2 which blew up on install. Tried to go back and it told me I had a pirated distribution (no way José) and to buy an authentic key.
Fortunately on reboot most of SP2 installed itself and I was able to go back and install the rest without problems. I've seen this "You have a pirated distribution" message before under similar failure circumstances.