Keep your system up to date with the most recent cumulative update package for SQL Server 2005 SP3. This package contains all of the SQL Server 2005 hotfixes that have been released since the initial release of SQL Server 2005 SP3.  SQL Server 2005 SP3 CU 15 marks the final Cumulative Update release for SQL Server 2005 SP3 during the mainstream support phase of the product lifecycle.  Details regarding end of mainstream support and support offering are outlined and available in a blog post at http://blogs.msdn.com/b/sqlreleaseservices/archive/2011/01/27/end-of-mainstream-support-for-sql-server-2005-and-end-of-service-pack-support-for-sql-server-2008-sp1.aspx .

Previous CU KB Articles:

Abhishek Sinha
Program Manager
SQL Server Sustained Engineering