Windows XP SP3 Release Candidate Now Available To PublicWindows XP SP3 Release Candidate Now Available To Public

Microsoft has released to the public a near-final version of a major update to its Windows XP operating system.

As of Wednesday, the 'Release Candidate' for Windows XP Service Pack 3 was available as a 336 Mbyte download from Microsoft's Web site. The software had previously been available only to participants in Microsoft's official test programs.

Software vendors usually issue a release candidate when they're close to producing a final version of a product or update. It provides a last chance for users to weigh in before a final version is released to manufacturing.

Microsoft says it considers the Release Candidate for Windows XP SP3 to be trial software and warns users to download with caution -- and at their own risk. "Microsoft does not recommend installing this software on primary or mission critical systems," the company states on its Web site.

For the adventurous, however, Windows XP SP3 Release Candidate offers a number of enhancements over the current version of the OS. It includes all updates issued since Windows XP Service Pack 2 was released in 2004, and some new elements.

Among them: A feature called Network Access Protection that's borrowed from the newer Windows Vista operating system. NAP automatically validates a computer's "health," ensuring that it's free of bugs and viruses, before allowing it access to a network.

Windows XP SP3 also includes improved "black hole" router detection -- a feature that automatically detects routers that are silently discarding packets. In XP SP3, the feature is turned on by default, according to Microsoft.

Windows XP SP 3 also steals a page from Vista's product activation model, meaning that product keys for each copy of the operating system doesn't need to be entered during setup. The feature should prove popular with corporate IT managers, who often need to oversee hundreds, or even thousands, of operating system installations.

Microsoft is in a bit of a Catch-22 with XP. The more it strengthens the OS, the less reason users have to upgrade to the newer Windows Vista, which by many accounts has failed to catch on with computer users in both the home and office since it debuted in January.

A final version of Windows XP SP3 is expected to ship early next year.