Update on Windows Service Pack Blocker Toolkit for Windows Vista & Windows XP

If you’re currently running Windows Service Pack Blocker on Windows XP or Windows Vista will expire as follows. The toolkit prevents automatic the installation of a service pack through Windows Update, typically for one year after general availability of the service pack.

Windows Vista SP1: April 28, 2009
Windows XP SP3: May 19, 2009

More info: Q&A