Microsoft has officially released Service Pack 2 (SP2) for Windows Vista and Windows Server 2008 for free public download via Microsoft Download Center and distribution via Windows Update. Earlier, the second service pack has been released to MSDN and TechNet subscribers too. Windows Vista SP2 and Windows Server 2008 SP2 is a single executable to update both operating systems. SP2 includes all previously released updates since Windows Vista SP1, in addition to support new types of hardware and several emerging standards.

Actually, Windows Server 2008 SP2 and Windows Vista SP2 has been finalized and released to manufacturing (RTM) since April 28, 2009 as build version 6002.18005.090410-1830, and both standalone update installer of Windows Server 2008 and Vista SP2 with all languages, and slipstreamed Windows Server 2008 with SP2 integrated DVD ISO or slipstreamed Windows Vista with SP2 DVD ISO integrated have been leaked weeks ago and available to download from BT network.

The current wave 1 release of Windows Vista and Server 2008 SP2 RTM is only applicable to computers that have one or more of the following languages: English, German, French, Japanese, or Spanish. There is only a single unified installer (2 installers actually, one each for 32-bit and 64-bit computer architecture) for Windows Vista and Windows Server 2008. The SP2 update can be installed on all editions of Windows Vista and Windows Server 2008, including Windows Vista Ultimate, Windows Vista Business, Windows Vista Enterprise, Windows Vista Home Basic, Windows Vista Home Premium, Windows Server 2008 Datacenter, Windows Server 2008 Enterprise, Windows Server 2008 Standard, Windows Server 2008 Web Server and Windows Server 2008 for Itanium-based Systems.

Update: All languages standalone updater version of Windows Server 2008 and Vista SP2 is now available.

Download Windows Server 2008 and Windows Vista SP2 x86 – Five Language Standalone Installer (KB948465)

Direct Download Link: Windows6.0-KB948465-X86.exe

Download Windows Server 2008 and Windows Vista SP2 x64 – Five Language Standalone (KB948465)

Direct Download Link: Windows6.0-KB948465-X64.exe

Download Windows Server 2008 and Windows Vista SP2 – Five Language Standalone DVD ISO (KB948465)

DVD ISO image that contains Service Pack 2 for Windows Server 2008 SP2 for x86, x64, IA-64 and Windows Vista for x86, x64. Again, the image is only applicable to computers that have one or more of the following languages: English, German, French, Japanese, or Spanish.

Direct Download Link: 6002.18005.090410-1830_iso_update_sp_wave0-RTMSP2.0_DVD.iso

Microsoft is expected to release wave 2 of Windows Vista and Server 2008 SP2 soon, which will contain updates for all localized languages available for the operating system. The Service Pack 2 will be delivered to all Windows Vista client and Windows Server 2008 server systems too via Automatic Updates, Windows Update or Microsoft Update as part of wave 3, normally few months after initial availability of SP2.

To install Service Pack 2, Windows Vista SP1 is a prerequisite for Windows Vista system. Windows Server 2008 released with SP1 included, and thus does not require any prerequisite installation. And all prerelease version of SP2 (such as SP2 Beta, SP2 RC or SP2 RTM-Escrow which are time-limited to expire the latest by June 1st, 2010) for Windows Vista and Windows Server 2008 must be uninstalled.

According to Things to Know Windows Server 2008 and Windows Vista SP2 article, if vLite was used to customize your Windows Vista installation, the error message “One or more system components that the service pack requires are missing” may be encountered when installing SP2, as some required system components may be removed, which prevent Service Pack 2 from installing. Solution is posted by Microsoft at KB968279. No further activation is required is the system state is already activated before upgrading to SP2. The system will stay activated and pass validation.

Also available for reading is FAQ for SP2, Release Notes for Windows Server 2008 with Service Pack 2, Release Notes for Windows Vista with Service Pack 2 and Notable Changes in Windows Server 2008 SP2 and Windows Vista SP2.