Microsoft has reversed its policy by opening public access to the latest beta build of Vista Service Pack 1.
Users can now download Vista SP1 RC Refresh from Microsoft's Web site.

Users can install the beta via Windows Update, but Microsoft is providing a list of procedures users should follow to avoid problems.

Microsoft originally released the Refresh beta on January 9 to approximately 15,000 beta testers that included corporate customers, consumer enthusiasts, software and hardware vendors, and others, according to a company spokesman.

The spokesman said on January 10 Microsoft decided to make the beta open to everyone with an interest via its TechNet Web site. Microsoft said its intention was to get the widest and deepest feedback it can before releasing the software.

The spokesman said Vista SP1 is still slated for release before the end of March.

The beta news comes on the heels of the third phase of a year-long study conducted by Walker Information for IT services and product supplier CDW, which shows Vista gaining popularity in the business market. The study shows that 48 percent of respondents are using or evaluating Windows Vista - up from 29 percent in the previous poll from February 2007 and from 12 percent in the first poll taken in October 2006.

Microsoft first made Windows Vista SP1 RC Preview available on Nov. 14 to 15,000 testers as part of its private beta program. In December, the company opened the beta to the public.

Microsoft hopes to align SP1's availability with Windows Server 2008, which Microsoft hopes to ship on or before its February 27, 2008 launch event in Los Angeles.

Vista SP1 will include a number of bug fixes and performance enhancements but no new features, Microsoft said. Microsoft also is updating its set of Vista migration tools, including the Application Compatibility Toolkit 5.0, Windows Vista Hardware Assessment 2.1 solution accelerator (formerly called Business Desktop Deployment), and Microsoft User State Migration Tools 3.0.

Microsoft officials said the Vista SP1 RC includes changes that streamline setup and installation. It also includes all previously released updates since RTM, performance and reliability improvements such as file copy, network browsing and improved response time to resume from sleep, and change to administration features, including changes to BitLocker that allow encryption for multiple volumes.

Over the years, SP1 versions of any Microsoft products have become a traditional milestone that some corporate users wait for before they even consider rolling out the software.

Uptake of Vista has been slow by corporate users, many of whom have standardised on XP and are reluctant to undertake another migration.