I got that error before I downloaded the genuine advantage tool.
I disabled my firewall. also, to my trusted sites I added the address of the download site. Microsoft should provide links to that article number to expain these steps for you.
click on sites
copy and paste the microsoft address to the zones.
That's what worked for me. However, once I downloaded SP3 my computer crashed. I ended up with a black screen, had to enable safe mode and do a system restore back to a few days ago. My other computer I first tried it on simply froze. I say to wait a while before you do this. I'm not going to do it at all. I will probably just upgrade to Vista. Hmm..makes me wonder if this is their plan.