Microsoft makes Vista SP1 available

The first service pack for Windows Vista has been released.

Vista Service Pack 1 (SP1) went onto Microsoft's Download Center Web site on Monday, fulfilling Microsoft's claim that it would be made available by mid-March. According to Microsoft, the service pack will be pushed out via automatic updates to all Vista users next month.

Standalone installers for both versions of Vista, 32-bit and 64-bit, have been made available.

According to Web retailer Amazon, boxed copies of Windows Vista with SP1 will be available on Wednesday in the US, and Amazon UK has the updated operating system listed for retail release on 4 April. However, Vista SP1 is available now from Microsoft's Download Center.

Vista SP1 is a roll-up of previous updates that have been pushed out to users of Microsoft's latest operating system since its release. The updates supposedly improve Vista's performance, but a prerequisite piece of software, labelled KB937287, had to be pulled by Microsoft in February as it caused problems with some third-party programs.

Microsoft admitted on its Vista team blog that users may still experience problems with drivers.

"We've completed our analysis and are happy to report that many of these issues were fixed between the release candidate [RC] and the final version," wrote Vista product manager Nick White. "We identified a small number of device drivers that may be problematic after an update from Windows Vista to Windows Vista SP1."

The list includes Symantec software drivers for Symantec Endpoint Protection and for Symantec Network Access Control clients. Symantec is aware of the situation, said Microsoft.

Microsoft had pegged mid March as the timeframe for SP1's release via the Windows Update site, with the service pack due to be automatically pushed out to users in April. However, even as late as Tuesday, when the download was live, there was still some confusion within Microsoft as to when the service pack would be available on Windows Update.

The pack was released to manufacturing on 4 February. The main features expected in SP1 are fixes to avoid incompatibilities with certain applications, as well as better reliability, security and performance.