When Microsoft finally rolled out the beta of its Windows Vista Service Pack (SP) 1 at the end of September, a new element of mystery was introduced. Microsoft officials said they were going to test simultaneously five additional reliability fixes that were not part of the SP1 beta - but that the team ultimately planned to add into SP1 before it shipped in early 2008.

As of today, we now know what the five additional updates are. Microsoft rolled out one of them on September 27 and delivered the rest of them over the past couple of days. All are now available on the Microsoft Download Center. Microsoft also plans to push the five out independently, via Windows Update, at some unspecified future time, officials said.

The five:

An MSXML Reliability Update (KB 941833, released to Download Center on 9/27). It is designed to resolve reliability and application compatibility issues in Microsoft XML Core Service 4.0 Service Pack 2.

A comprehensive reliability, compatibility and stability update (KB 941649). It addresses everything from battery life to startup time of the operating system.

A fix pack for Windows Media Player 11 (KB 941651), which will "improve the reliability of Windows Media Player 11 for Windows Vista in certain scenarios."

A USB update (KB 941600) which "resolves some reliability issues in the USB core components on the Windows Vista operating system."

A cumulative update for Windows Media Center (KB 941229), addressing a variety of bugs in the Home Premium and Ultimate SKUs.

News source: ZDNet