Microsoft on Monday announced the completion of Windows XP Service Pack 3 (SP3), the final service for the aging and soon-to-be-discontinued desktop operating system. Windows XP SP3 will make its way to PC makers and Microsoft's enterprise customers in the coming weeks, the software giant says. Individuals who wish to download the update can do so begin April 29.

"We are happy to announce that Windows XP Service Pack 3 has released to manufacturing (RTM)," wrote Chris Keroack, the release manager for XP SP3, in a posting to Microsoft's TechNet site. Keroack also spelled out a rough release schedule for the service pack, which begins with the April 29 manual download availability and ends with an "early summer" broad release via Windows Update. A separate Microsoft post, since removed placed the Windows Update availability on June 10, however.

Here's the complete Windows XP SP3 release schedule:

RTM (release to manufacturing): April 21
OEM channel: April 21
Windows Update (optional update): April 29
Microsoft Download Center: April 29
MSDN/TechNet download: May 2
Windows XP SP3 fulfillment media (CD-based): May 19
Volume license customers download: June 1
Windows Update/Automatic Updates: June 10

For more information, please see my Windows XP SP3 FAQ and RTM screenshots on the SuperSite for Windows.