Windows Server Update Services with Service Pack 1 (WSUS SP1) delivers updates for WSUS. This service pack includes support for Microsoft SQL Server 2005 and the forthcoming Microsoft Windows Vista operating system, and provides additional stability and performance improvements. After you install WSUS SP1, you may be required to restart your computer. You cannot remove WSUS SP1 after you install it.

What's New in WSUS SP1

WSUS SP1 is a service pack release that improves the security, reliability, scalability, compatibility, and performance of WSUS. This service pack includes the following new features and improvements:

  • Windows Vista support - WSUS SP1 allows your customers to update computers running Windows Vista
  • Full client language support. WSUS SP1 supports all Microsoft Office and Windows Vista languages
  • New version of WMSDE. WSUS SP1 upgrades WMSDE from WMSDE SP3 to WMSDE SP4
  • Faster performance. WSUS SP1 improves performance, including accelerated user interface response times.
  • All hotfixes. WSUS SP1 includes all changes and hotfixes issued since the release of WSUS
  • Support for SQL Server 2005. WSUS SP1 allows your customers to use SQL Server 2005

http://www.microsoft.com/windowsserversystem/updateservices/downloads/WSUSSP1.mspx