The update provides, among other things support for Bluetooth 2.1, an updated Windows search technology and the ability to natively record data to Blu-ray discs.
In a blog posting, the company said the update should be publicly available later this quarter. Microsoft is also ending a blocker tool that prevented computers from downloading Vista Service Pack 1, so those customers who had been using the tool will now see Vista SP1 offered via Windows Update.
Microsoft said earlier in the day that it was releasing the second service pack update to Office 2007. Windows Vista and Office 2007 had their mainstream launch on the same day in January 2007.