It appears SP3 RC2 is available for Windows XP via Windows Update.

Previously only available to some thousands of beta testers a few weeks ago, Service Pack 3 adds several networking and security improvements, and compatibility with Windows Vista and Windows Server 2008 security credential providers. It also incorporates features previously available individually as separate updates, such as Micorsoft Windows Imaging Component (WIC), Microsoft Management Console (MMC) 3.0, and Wi-Fi Protected Access 2.

A list of all the features can be found on the Microsoft website.

Note: It is important to uninstall any previous versions of SP3 from your PC before installing this one.  This can be done from Add/Remove Programs in the Control Panel.

Windows Vista Service Pack 1 will make some well-known third-party security applications “experience a loss of functionality”, confesses Microsoft in a Knowledge Base article.

Popular applications include ZoneAlarm Security Suite, Trend Micro Internet Securiy and BitDefender AV or Internet Security.  A fuller list of programs, including specific program versions, can be found in the KB article.

Microsoft said in the article: “A program may experience a loss of functionality after you install Windows Vista SP1. However, most programs will continue to work as expected after you install Windows Vista SP1.”

Note: Microsoft says that the KB article: “should not be considered a comprehensive list of programs that experience loss of functionality when they run on a Windows Vista SP1-based computer.”

Microsoft has released Windows Vista Service Pack 1 to manufacturers.

SP1 is a bundle of fixes including extra hardware drivers, and possibly more importantly, fixes for a number of high profile bugs.

It also changes aspects of the controversial Windows Genuine Advantage software integrated with the operating system, which checks if the computer is running a “genuine” version of Windows.  WGA will continue to show warning messages if it believes the license is not genuine, but it will no longer shut down core functions of the PC.

Home users can expect to see a release to Windows Update around early- to mid-March.