Microsoft has started recruiting testers for the first beta of Windows Server 2003 R2 - an update it plans to ship in October next year.

The beta test period will start soon, according to a posting on Beta Place, Microsoft's beta website. At least some of the prospective testers were invited to trial the Windows Server update because they also tested Windows Server 2003 Service Pack 1, according to Neowin.net, a Microsoft enthusiast website.

This first beta test will start this month, but will be limited to about 1,000 testers, a Microsoft spokeswoman said. A second, public beta is planned for the first half of next year.

Windows Server 2003 R2 is an interim release of Windows Server built on top of Windows Server 2003 SP1. It will include most of the feature packs Microsoft released since the initial Windows Server 2003 release in 2003, including Active Directory Application Mode, Windows SharePoint Services, and Automated Deployment Services.

The interim release is intended to fill the gap between Windows Server 2003 and Windows Server Longhorn, which is set to ship in 2007. Microsoft clarified its Windows Server road map in May. Plans call for a major release roughly every four years and an incremental update two to two-and-a-half years after each major release.

Microsoft gave a sneak preview of Windows Server 2003 R2 at its Tech Ed user conference in San Diego last May. The vendor demonstrated several features, but in October revised its ambitions for the Windows Server update by axing some of them.

It showed off Network Access Protection (NAP), which lets administrators ensure a computer joining a network meets security and configuration requirements. NAP won't ship next year as planned, but will now be included in Longhorn Server.

While service packs are available at no charge, the R2 update will not be, Microsoft has said. Companies that bought individual licenses for earlier Windows Server products will have to buy a new license for R2. Customers who have purchased Software Assurance, Microsoft's software maintenance plan, will receive the update at no extra charge.

Word of the R2 beta follows the release to testers of a release candidate of Windows Server 2003 SP1 earlier this week. A release candidate is a near-final version of the service pack, which is slated for final release in the first half of 2005. SP1 is a security-focused upgrade for Windows Server 2003.