A. XP SP2 includes many great new features; the downside is that it can cause problems with running some programs. Consequently, some customers want to prevent their systems from automatically downloading XP SP2 until they've tested the service pack thoroughly and are better prepared to deploy it. Microsoft understands this and provides detailed guidance about blocking the automatic delivery of XP SP2 via Windows Update and Automatic Updates at http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2aumng.mspx. The methods described on this Web page will work until April 12, 2005, at which time Windows Update and Automatic Updates will deliver XP SP2 regardless of whether the blocking mechanism is present on a system. (That date is also the scheduled date for a monthly cumulative security update.)

You can download a tool that blocks delivery of XP SP2 at http://go.microsoft.com/fwlink/?LinkId=33517. The download includes an executable file, a script and Group Policy administrative template, and some sample email messages that you can send to users; the sample messages contain links users can click to either block or unblock the delivery of XP SP2. XP SP2 blocking is controlled through the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\DoNotAllowXPSP2 registry subkey. Setting the subkey's value to 1 blocks delivery of XP SP2 through Windows Update or Automatic Updates on that system. Be aware that this registry change will work only until April 12, 2005, as well.