Although the final upgrade to the Windows XP operating system was supposed to be made available this week on Microsoft’s Download Center, Microsoft has apparently decided to delay its release. Service Pack 3 was originally released to manufacturing on April 21 and plans were set for May 2 to make the upgrade available via MSDN and Technet download.

The issue cited by Microsoft relates to compatibility problems between SP3 and the Microsoft Dynamics RMS for small and midsize businesses. The glitch also affects Windows Vista Service Pack 1, which Microsoft began pushing out for automatic updates last week.

The SP3 upgrade includes a variety of bug fixes and other minor enhancements to the Windows XP operating system. Several Windows Vista features are also included, such as Network Access Protection, “black hole” router detection, and the Microsoft Kernel Cryptographic Module. The SP3 service pack also incorporates all fixes made in prior versions.

The laundry list of operating systems covered by the service pack includes Windows XP, Windows XP Home Edition, Windows XP Home Edition N, Windows XP Media Center Edition, Windows XP Professional Edition, Windows XP Professional N, Windows XP Service Pack 1, Windows XP Service Pack 2, Windows XP Starter Edition, and Windows XP Tablet PC Edition. The download size is between 428KB and one megabyte, depending on which components are selected.