Microsoft will begin pushing out Vista SP1 to users via its Automatic Update service this week, following comments made by Bill Gates that suggested the next major Windows version might appear as early as next year.

Vista SP1 is already available for download via Microsoft's Windows Update service, but the company has confirmed that the service pack will now be pushed out as an automatic update starting from mid-April.

Companies wishing to deploy SP1 in a controlled fashion will need to block it from downloading automatically, unless they already disable updates as part of company policy.

Earlier, Microsoft had suspended distribution of an update that is a pre-requisite for SP1 to be downloaded. Some users experienced difficulties while installing the Servicing Stack Update patch, but Microsoft said it has now issued a fix for the problem.

Microsoft chairman Bill Gates has also added fuel to speculation that the planned successor to Vista, Windows 7, may be brought forward from its expected release date in 2010.

While speaking at the Inter-American Development Bank in Florida, Gates is quoted as telling the audience that "sometime in the next year or so we will have a new version." Gates was referring to Windows 7, but it remains unclear whether he meant the complete version or a beta release will be available in 2009.

Microsoft said that Windows 7 is still "scoped to three years from Windows Vista's general availability", which suggests a release date in the first quarter of 2010. It added that it had no further information to disclose at this time.