Windows Vista SP1 is available on TechNet and MSDN subscriptions now. TechNet Plus and MSDN subscribers can now access Windows Vista SP1 in the Top Subscribers Download section on the subscriptions home page.
Subscribers, Login to get :
For TechNet Subscribers
For MSDN Subscribers
And please check the 'Top Subscribers Section' as said earlier for these downloads, as some of the subscribers are not able to locate.