SQL Server 2005 SP3 released today after the release of SP3 beta a couple of weeks ago. You can download SP3 from the link below.
Above download link is applicable to below products.
* SQL Server 2005 Enterprise
* SQL Server 2005 Enterprise Evaluation
* SQL Server 2005 Developer
* SQL Server 2005 Standard
* SQL Server 2005 Workgroup
For Express edition check the link http://go.microsoft.com/fwlink/?LinkId=64064 for SP3.
For a list of new features and improvements that are included in SQL Server 2005 SP3, review the What’s New document.
Once the server is patched with SP3, SQL Server version will be changed to 9.00.4035. You can use the below query to check it.
SELECT SERVERPROPERTY('ProductLevel')
SELECT SERVERPROPERTY('ProductVersion')