Microsoft has released a toolkit to let businesses block service pack updates for Windows XP, Vista and Server 2003.
Although service packs  particularly in the case of Vista  are keenly awaited by many users, some businesses prefer to test the packs before upgrading to assure compatibility with existing hardware and applications.
The Windows Service Pack Blocker Toolkit will allow this to happen by stopping Windows Update from automatically downloading and installing the service packs.
Read more: ZDNet.co.uk