Microsoft has issued the final test version of its forthcoming Windows Vista operating system. 

The Release Candidate 2 code is currently available only to a select group of beta testers, but will be offered through the Microsoft Developer Network and Microsoft Technet programme for IT staff.

Windows boss Jim Allchin said in an email to developers that the new version offers "thousands of quality improvements" over the Release Candidate 1 unveiled in September. 

New features include increased performance and better application compatibility, according to Allchin.

"We are just around the corner from release to manufacturing [RTM] and shipping this great product to the world," he wrote. "This will be the last build made available prior to RTM."

Allchin urged partners to test the software for deployment and to certify their systems for the Windows Vista logo programme.

Enterprises and PC manufacturers can expect to receive the final version of Windows Vista in November. The consumer launch is scheduled for January 2007.