Microsoft on Tuesday said that it has reached the "release candidate" with the first service pack for Windows Vista, with plans to make the test software available publicly next week.
It is releasing the test code this week to the 15,000 or so people who have been beta testing SP1 already, and will also make it available on Thursday to those in the MSDN and TechNet developer programs.
"We feel really good and we look forward to receiving feedback from our larger set of testers," said David Zipkin, a senior product manager on the Windows Client team.
Microsoft also said on its Vista blog on Wednesday that it will make available a "blocker" that will allow customers who have Vista and use Windows Update to block SP1 upon its final release to allow for further testing. Microsoft offered a similar option with Windows XP Service Pack 2.
Service Pack 1 is mainly designed as a collection of bug fixes and performance improvements rather than an attempt to add new features. Among the changes that are more feature-related is the ability to use BitLocker encryption on multiple hard drive volumes as well as changes to the desktop search feature, which were made to satisfy antitrust concerns from Google.
Microsoft also said this week that it will change the way its antipiracy features work in SP1, eliminating a system in which Vista machines found not to be genuine are relegated to a near-unusable "reduced functionality mode." In its place, Microsoft will show prominent warnings and prompt those with non-genuine software to get a properly licensed copy. The new antipiracy approach will be in the final version of SP1 but is not part of the release candidate version.
The software maker has made some changes to SP1 since it began testing it earlier this year. In particular, the company has worked to reduce the size of the update as well as the amount of free space required to perform the update.
Vista still requires up to 4.5GB of free space for a typical user, but that's down from the 7GB required in earlier beta versions. Most of that space is returned back to the user. For some people, though, particularly those with ultramobile machines or running Vista in a partition on their Mac, the free space limit can be an obstacle.
Microsoft has also significantly reduced the file size of the Windows Update and full versions of the service pack, Zipkin said.
The release candidate version of the Vista service pack comes just as the Windows Server team issues a public release candidate for Windows Server 2008. Development of Vista SP1 and Windows Server 2008 have been fairly closely aligned and both are slated for release in the first quarter of 2008. However, Zipkin said it is conceivable the release of the two products could vary, particularly if quality concerns arise for either one.