Microsoft is expected to roll out to testers, the week of April 17, a new test build of Windows Vista.

Microsoft is expected to make available for download the new release, Build 5365, by Technology Adoption Program (TAP) and TechConnect testers this week, according to Vista testers.

Build 5365 is not the build once known as the April Community Technology Preview (CTP). That build, now expected by testers to arrive some time in May, is also known as the Vista Consumer CTP, and is expected to go to more than two million testers. Microsoft is not providing a firm date for that CTP build, other than to say it will arrive some time in the second calendar quarter.

Build 5365 is a much more modest update, known as an EDW, or or External Developer Workstation, build. Microsoft releases these builds -- which are typically rougher and less thoroughly tested than CTPs – to a smaller, selected set of testers on a regular basis.

Build 5365, according to various Windows enthusiast sites around the Web, includes primarily cosmetic updates and fixes. According to one such site, H/D News, the build will include Sidebar fixes; support for more Gadgets; "Welcome Center" changes, as well as install and driver support improvements.

When asked for comment on the new build, a Microsoft spokeswoman provided the following company statement:

"We are considering releasing updated Windows Vista code to Windows Vista Technical Beta program participants as well as select TAP customers. In addition to the CTPs, we sometimes provide a select group of testers with current pre-release versions of Windows Vista based on their feedback and testing needs. These builds are not CTPs.

"As we have said, the next CTP will conclude the Beta 2 process and will be called Beta 2. We are on track to deliver Beta 2 in the second quarter of this year."

On Monday afternoon, according to one Web report, Microsoft officials said the new 5365 build would not be posted on Monday the 17th, after all. The update does not offer a firm date, but does say the new build is coming.

The last interim build Microsoft released was the EDW it delivered on March 24. That Vista test build, number 5342, also included primarily user-interface tweaks.

Over the weekend, some Windows sites posted screen shots of another interim Vista build, number 5361.

Microsoft is expected to continue to make EDWs available to a subset of TAP and TechConnect testers on a regular basis, as the product moves toward completion.

Microsoft officials have taken to referring to the partner/December CTP; the enterprise/February CTP; and the consumer/May CTP collectively as "Beta 2." There will be no single, traditional Vista Beta 2 release, however. Following the release of the May CTP, Microsoft is expected to roll out a number of various, smaller technical betas until the product is finished.

Microsoft officials have said Vista will still be released to manufacturing this year, and that business users with volume-license agreements will be able to take delivery of the code in November. The official Vista launch – and worldwide availability of all versions of the product for all customers – currently is slated for January, 2007.

This story was updated on April 17 to include new information on the availability date for Vista Build 5365.