The first Release Candidate of Windows Vista Service Pack 1 is here, and Microsoft will make available a public build of the development milestone the coming week. On December 5, the Redmond company dropped Vista SP1 RC via Microsoft Connect, opening up the build to MSDN and TechNet subscribers today, on December 6. In addition to these locations, Vista SP1 RC will hit the Microsoft Download Center in just a few days, come December 10. Nick White, Microsoft Product Manager working with the Vista launch team, has revealed that by this stage of development Vista SP1 can be considered as close to finish as possible. White indicated that the next move for Microsoft would be to release Vista SP1 to manufacturing, and stressed increased levels of performance and stability for the service pack.

"The size of the standalone installers have decreased significantly. For example, the standalone installer packages consisting of all 36 languages (x86 and x64 chip architectures) are smaller by over 50%. The standalone installer packages consisting of just the 5 languages (again, x86 and x64) slated for initial release are more than 30% smaller in size. The required amount of disc space for SP1 installation has also decreased significantly. Furthermore, with the RC, if more space is required to install SP1, an error message will now display exactly how much space is needed to complete the installation. Previous SP1 versions left behind a directory of files that wasn't needed after installation and occupied about 1GB of space; the RC includes automatic disk clean-up to remove this directory", White enumerated some of the modifications delivered by RC1 in comparison to the Beta builds of Vista SP1.

But, most of all the Redmond company has focused on improving the installation experience with Vista SP1 RC. White noted a boost in reliability, as well as the addition of extra guidance from Windows Update. Now, users can benefit from a succession of screens displayed during the installation process of Vista SP1 RC. At this point in time, it is clear that Microsoft will open up the Release Candidate for Vista SP1 quite soon. But at the same time, going public with Vista SP1 RC means that the service pack is as close to finalization as possible. This could, in fact, be an indication that Vista SP1's release in the first quarter of 2008, might be close to January-February.