With Vista and Windows Server 2008 shortly to become the focus of a shared SP2 release (currently guesstimated for April, 2009), this tool retains its capability and may be used to block or defer installation of this new SP for up to 12 months after its eventual general availability date. The Blocker offers admins three different ways to manage Service Packs:

• An MS-signed executable that manages a Registry Key (in HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate) to block or allow Windows Update delivery of a current SP.
• A script that works like the MS executable except that it allows the admin to supply the name of a remote machine where the block/unblock operations may be performed.
• An administrative (.ADM) template that permits admins to import GPOs to block or unblock delivery of SPs into a Group Policy environment.

As Microsoft observes in connection with the Blocker “this toolkit will not prevent the installation of the service pack from CD/DVD, or from the stand-alone download package. This simply prevents the service pack from being delivered over Windows Update.”

For environments where more time is often needed to test and accommodate SPs, the Blocker can be a handy tool. As long as admins understand it does not last forever–in fact, a year from the SPs general availability date is as much leeway as it can provide–the tool can be a useful element in their Vista, XP, and Windows Server 2008 toolbox.