The long-awaited first Service Pack for the Microsoft Windows Vista operating system is a step closer to availablity.

The SP1 has gone live as a "release candidate" level download on Microsoft's site.

This means it is in sort of a public beta phase, although those that would consider themselves firmly consumer-level when it comes to software updates would be much better off to wait for the actual official release.

This is still scheduled for launch in Q1 2008, with a January release most likely, a year after the operating system was actually launched.

The patch will contain changes focused on addressing reliability and performance issues Microsoft has identified via customer feedback, supporting new types of hardware, and adding support for several emerging standards.

SP1 also promises to make additional improvements to the IT administration experience, hopefully boosting Vista's enterprise appeal.