In a separate announcement, Microsoft also unveiled the first Beta of Windows Server, code-named Longhorn.

Allchin, who earlier this year announced he would retire from Microsoft at the end of 2006, has been a driving force behind Windows client and server platform development since joining the company in 1990 -- the same year Windows first shipped. In addition to dishing up the Vista Beta 2 DVDs, Allchin noted that Microsoft's WinFX APIs, developed for Vista, will be made available for Windows XP. Microsoft has also committed to releasing Vista's Windows Presentation Foundation -- its graphics subsystem -- and Windows Communication Foundation, a major extension to the .Net framework for transactional Web services, for Windows XP.

Windows Vista Beta 2 build 5384 will have the widest distribution of any prerelease version of Windows Vista. Microsoft will offer Beta 2 publicly for consumers via a DVD mailed on request.

Attendees at the reviewers workshop, which was held in a hotel blocks away from Microsoft's Windows Hardware Engineering Conference (WinHEC), were given a quick look at usability refinements to the new User Account Control features in Windows Vista Release Candidate 1, which is expected to follow Beta 2 in early summer. User Account Control is a set of functions aimed at making it easier for Vista users to use a limited-system-privileges "Standard log-in" instead of the far less secure Administrator log-in.

According to Allchin, Microsoft is on track to deliver Windows Vista to the corporate market in November and to release it to PC manufacturers and retail distributors for availability in January. When asked which versions of Vista would sell well and which markets would be quickest to adopt it, Allchin projected that OEM PC makers would move to Vista rapidly, with consumers the first to adopt it. In contrast, many corporations are more likely to test the Vista waters before diving in later.