Microsoft has released a refresh of Windows Vista Service Pack 1 (SP1) to beta testers, indicating the final release might be near.

Beta users of SP1 have received an email from Microsoft alerting them that Vista SP1 refresh 2 is available for download. Microsoft released the latest build, which addressed a small number of bugs that testers encountered in the previous version, to around 15,000 beta users, the company said.

Microsoft issued Vista SP1 Release Candidate in December and a refresh earlier this month. It has said that the final Vista SP1 will be available to the public during the first quarter of this year, with some reports suggesting that it might come out as soon as February 15.

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The fact that Microsoft even has a beta of SP1 and has now issued two refreshes to it indicates that the company is trying to be very careful in testing the software and ensuring compatibility, said Andrew Brust, chief of new technology for consulting firm twentysix New York. "It is working hard to under-promise/over-deliver," he said. "Given the dynamics around the initial release of Vista, that is a prudent course to pursue."

Because it's quite unusual to issue a beta and multiple refreshes, Microsoft is likely very close to issuing the final public version of SP1, Brust said.

That will depend, however, on any problems that testers may find in the newest refresh. If something is broken, Microsoft will have to spend time fixing it, said Chris Swenson, an analyst at NPD Group. "We're just in wait and see mode," he said.

The release of a second refresh doesn't provide many more clues about when to expect the final version of SP1, agreed Michael Cherry, an analyst with Directions on Microsoft. "The only thing is that we know it is making progress, but we don't know how close it is," he said

Still, the initial indication from people who have been testing SP1 is that it's pretty solid so it's reasonable to think the final version might come out in a couple weeks, Swenson said.

The final public release of SP1 could boost Vista sales, at least among business users, since some companies have said they are waiting for the release of SP1 before upgrading from XP to Vista. Consumers, however, don't appear to have decided to wait. Retail PC sales were up last year and less than 1 percent of all computers including Macs that sold in retail outlets last year had XP, Swenson said. "It's more of an issue for businesses," he said.

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