Where did you get your SP3?
I got one from MajorGeeks.com, but it errors out.
Since I work as a Windows admin and need to keep my skills up, it a good fit for me.
You can check it out here.
Incidently, I found a $100 coupon off the initial price of $349 from this article, although I think it's only good till May (not sure if that means May 1 or May 31).
I downloaded mine from Majorgeeks also after reading your post.
It downloaded, then installed and rebooted, NO PROBLEMS AT ALL!!
Took about 30 mins and here I am. :-)
But funny, its now got a desktop background of Jackie Mason Boinking Pelosi!?!?! Geee.....
Not true, but it installed without a hitch. Piece of cake.