Microsoft is still far from wrapping up with the third and final service pack for Windows XP, just the 32-bit version of Windows Vista's predecessor. And, at the same time, XP SP3 failed to have anything close to a smooth ride, although it did manage to veer away from the speed bumps hit by Windows Vista Service Pack 1. Over two months since XP SP3 became accessible to users of the operating system, Microsoft is detailing no less than five broken installation scenarios. According to the Redmond giant, in specific situations, the install option for XP SP3 RTM will not be available when the gold bits of the service pack are accessed through Windows Update or Automatic Updates. The final version of XP SP3 is indeed available through both WU and AU, but Microsoft outlined five situations in which the deployment option is absent.

"This problem has one or more of the following causes. Windows XP SP3 is already installed. A beta version of Windows Internet Explorer 8 is installed. Your computer is in an environment where your network administrator manages the installation of service packs and updates. The following scenarios are true: your computer uses an AMD processor - additionally, the copy of Windows XP that is running on your computer is deployed by using an Intel-based Windows image; and your computer previously used an Intel processor - additionally, your computer is running Windows XP. Then, you later upgraded your computer to use an AMD processor. You have one of the following Symantec products installed: Norton System Works; Norton 360; Norton AntiVirus 2008, additionally, the version of the Symevent.sys file is earlier than 12.5.4.1," Microsoft revealed.

If SP3 is already installed, it is only logical that WU and AU will no longer offer the service pack. However, the same is valid for the users running Internet Explorer 8 Beta 1. Because SP3 is virtually stuck in the past, bringing Internet Explorer 6, its installation on top of XP copies with IE8 Beta 1 integrated will cause the development milestone of the browser to become a permanent component of the platform. Users will no longer be able to uninstall IE8 Beta 1 after the implementation of XP SP3 RTM. In order for SP3 to become available on WU and AU, users will have to remove IE8 Beta 1 first.

Microsoft additionally informed that Windows XP-based computers running in managed environments could be protected from the delivery of SP3 through Windows Update and Automatic Updates with the Windows Service Pack Blocker Tool. XP SP3 also fails to play well when it comes down to integrating into XP images built with System Preparation on Intel computers and then deployed on AMD machines. Microsoft offers update KB953356 to resolve this specific issue before SP3 is available through WU and AU. As far as Symantec's products are concerned, the Cupertino-based security company has updates in place designed to resolve any incongruence with XP SP3.

"If the Windows Update Web site or Automatic Updates still does not offer Windows XP SP3, you can download and install the stand-alone version of Windows XP SP3. The stand-alone version of Windows XP SP3 does not verify the issues that prevent the Windows Update Web site and Automatic Updates from offering Windows XP SP3 to you. In some cases, the Windows Update Web site and Automatic Updates protect your computer by not offering Windows XP SP3 to you. For example, if a beta version of Internet Explorer 8 is installed on your computer, you might not want to install the stand-alone version of Windows XP SP3," Microsoft added.

- Windows XP Service Pack 3 stand-alone version is available for download here.
- Windows XP Service Pack 3 Checked Build Network Installation Package is available for download here.
- Windows XP Service Pack 3 CD Image is available for download here.