I was about to install the SP2 from SQL Server when things started to give me woes with all sorts of issues. I wanted to uninstall and then tried to figure out the version and what SP did I have, when I realized, how difficult some little things could be. You can figure this out in two different ways:
#1 In SQL Server Management Studio Object Explorer when connected to the instance.
#2 By executing the query SELECT SERVERPROPERTY('ProductVersion') against a Database Engine instance.
The following table shows the version numbers that correspond to versions of SQL Server 2005:
Version Number SQL Server Version
9.00.1399 SQL Server 2005 (initial version)
9.00.2047 SQL Server 2005 SP1
9.00.3042 SQL Server 2005 SP2
