Yesterday, I reported that Microsoft had made its final Windows XP service pack, SP3, available to the public via its Microsoft Downloads Web site. Since then, the company discovered an incompatibility between XP SP3 and its Microsoft Dynamics Retail Management System (RMS) software. So it has delayed the release of XP SP3 to both Microsoft Downloads and Windows Update.
"In order to make sure customers have the best possible experience we have decided to delay releasing Windows XP SP3," a Microsoft spokesperson told me, noting that the Dynamics RMS issue affects Windows Vista SP1 as well. "We plan to put filtering in place shortly to prevent Windows Update from offering both service packs to systems running Microsoft Dynamics RMS. Once filtering is in place, we expect to release Windows XP SP3 to Windows Update and Download Center."
That said, you can still download Windows XP SP3 via the direct download link. This is the 316 MB standalone installer package.