Microsoft SQL Server 2005 Service Pack 3 (SP3) contains hotfixes that were included in cumulative update packages for SQL Server 2005 Service Pack 2 from cumulative update package 1 to cumulative update package 9, and fixes to issues that have been reported through our customer feedback platforms. It also includes supportability enhancements and issues that have been reported through Windows Error Reporting.
Review what's new in SQL Server 2005 Service Pack 3 for information on new or improved features in Database Engine, Notification Services, Replication and Reporting Services.
Review the SQL Server 2005 Service Pack 3 Fixlist article in the Microsoft Knowledge Base for information on bug fixes in SP3.
Note: If you are upgrading from SQL Server 2005 SP2 Cumulative Update 10 or Cumulative Update 11, you must apply a post-SP3 cumulative update after upgrading to SP3 to get all the fixes.
Link to download SP3 for SQL Server 2005: http://www.microsoft.com/downloads/details.aspx?FamilyID=ae7387c3-348c-4faa-8ae5-949fdfbe59c4&displaylang=en