The new version is referred to as build 5472 and marks the first update since Microsoft ended public availability of the software.
The update offers performance improvements, bug fixes and feature enhancements requested by testers of earlier versions.
The new version improves the responsiveness of the Media Centre features in the software, and introduces support for Media Center Extender technology that allows consumers to access media on their computers through the Xbox 360 or standalone Extender devices.
Microsoft also unveiled a new pre-release version of its Windows Vista Software Development Kit that allows developers to craft applications for the latest Vista build.
Windows Vista is scheduled for public availability by January 2007. A first release candidate has been promised for the third quarter of this year.
The skeleton was unearthed more than 20 years ago in South Africa
Moon's dark side is mountainous, rugged and never visible from the Earth
The groundwater basins in some areas of Tehran have been damaged irreversibly
This is the first time that any spacecraft on Mars has recorded air vibrations on the planet