IT shops have been kicking and screaming since last August, avoiding Windows Service Pack 2 at all costs. Those days are over—you can no longer refuse to drink the Kool-Aid (although, in my experience, it’s been a pretty secure, stable Kool-Aid).
INFOWORLD – Shortly after the August, 2004, release of Windows XP SP2, Microsoft posted several tools that allowed companies and individuals to block Automatic Update and/or Windows Update from automatically downloading and/or installing SP2. Those tools eventually used a built-in expiration date of April 12, 2005.
The only way to keep your copy of XP pristine is to shut off Automatic Updates, but then expect to see a PC-based worm farm almost immediately.
Microsoft Turns Off XP SP2 Blocking [InformationWeek]