A beta version of the first service pack for Windows Vista is due over the next few days, according to sources close to Microsoft.

Microsoft has remained tight-lipped about the details of Windows Vista SP1 (Service Pack 1) - a rollup of updates for the OS. The company has not said when the software will be in final release, with the latest from the company revealing only that a beta will be out sometime before the end of the year. Many expect the final version of Windows Vista SP1 to be released in November.

However, the WinBeta.org blog reported in a post that Microsoft 's Windows Driver Kit (WDK) team sent out an email to beta testers that a new build of the WDK was being released to them to coincide "with the recent OS beta release for Vista SP1 Preview", hinting that SP1 beta is soon to be sent to testers.

Others speculate Microsoft might release the SP1 beta today, to coincide with its fiscal 2007 fourth quarter and year-end financial results.

In an interview yesterday one source close to the company said he had been told by insiders that a beta of SP1 would be out by now, so an imminent release is highly likely. And another said that beta testers report SP1 will definitely be out this week, with a final release coming in November or December.

At Microsoft's Worldwide Partner Conference in Denver two weeks ago, Mike Sievert, corporate vice president of the Windows business group at Microsoft, toed the party line on Vista SP1 and said little about when it would be released or what would be in it, and hinted that Microsoft's own plans for the service pack are still in flux.

Sievert also downplayed the software's role in when some Windows users will upgrade to Vista, though it's widely known many users - especially business and enterprise customers - are waiting for SP1 before replacing Windows XP with Vista.

"Most companies are still in the evaluation phase," he said in an interview. "Service pack or no service pack, they're still looking at what they will deploy."

See also:

Windows Vista review