August 16 was set to be D-day for the automatic delivery of Microsoft's Windows XP Service Pack 2 (SP2).

But at the last minute, the Redmond software vendor decided to push back by at least nine days the Windows Update/Automatic Update launch date for its collection of security fixes and features. Microsoft cited customer demand as the reason for the delay. A number of corporate customers are not ready to deploy SP2 and need to use Microsoft's recently introduced toolkit for temporarily blocking SP2 delivery until they can adequately test the release with their custom and third-party software.

Microsoft just published a list of about 50 software applications —some from Microsoft, others from third-party vendors — that may not work properly with Windows XP SP2 without users performing manual modifications.

Microsoft notified corporate customers of the SP2 delivery delay via a note sent out on Monday. Microsoft Most Valuable Professional Steven Bink published the text of the note on his Web site.

"Since some of our customers, such as your organization, utilize Automatic Update for a collection of your PC's, and since your organization may not yet be prepared to deploy Windows XP SP2 onto those machines, we recently made available a mechanism for temporarily blocking the download of Windows XP SP2 to those machines using Automatic Update.

"Last week, we received feedback from our corporate customers that they would like more time to put this temporary blocking mechanism into place," the Microsoft note continued. "Based on that feedback, we have altered the delivery schedule of Windows XP SP2. The machines in your organization using Automatic Update will not receive Windows XP SP2 until Wednesday, August 25 — at the earliest — as long as those machines are running Windows XP Professional Edition."

Microsoft officials did not respond to a request for further elaboration on the delay by the time this article was published.

Individuals running Windows XP Home Edition got a shorter reprieve. Microsoft will begin pushing SP2 to them automatically on Wednesday, August 18, according to the Microsoft note.

Microsoft did begin pushing SP2 out to some corporate users on Monday, however. Those who use Microsoft's Software Update Services patch service, rather than Windows Update/Automatic Update, began receiving the SP2 update bits on August 16, as previously scheduled.

Microsoft released SP2 to manufacturing on August 6. Microsoft already has made the update available to customers who had been beta testing the service pack and to developers. PC makers and retailers are expected to begin offering SP2 this fall.