The vague timetable that Microsoft gave Monday for pushing out Windows XP SP3 to most users got specific Tuesday as the company quietly said it would release the upgrade on Thursday at 10 a.m. PDT. Microsoft will add Windows XP Service Pack 3 (SP3) to Windows Update at that time, and trigger its automatic download and installation for users who have left the operating system's update service at its default "Automatic (recommended)" setting. "Updated applicability rules and updated metadata to target the update to Automatic Update channel," read a Microsoft support document revised Tuesday after the company unveiled its monthly security patches . "The Automatic Update change will be published at 10:00 A.M. on July 10." Monday, a Microsoft manager said only that XP SP3 would be automatically downloaded and installed "shortly," but did not specify a date. Microsoft delayed the distribution of Windows XP SP3 twice this spring, but the July 10 date seems firm; it was included in the cumulative list of all updates available via Windows Server Update Services (WSUS), the server-side update tool many businesses use, as well as via the client-side Windows Update (WU) and Microsoft Update Web-based services. A Microsoft spokeswoman, however, was not able to immediately confirm that July 10 will, in fact, be XP SP3's automatic update debut. In late April, Microsoft postponed the release of XP SP3 because it found a compatibility bug between ...