SQL Server version @@ version

A handy query to let you know the version with the service pack of the SQL Server you are running.

Just log on to the instance, open the query editor and run this query

select @@version

Output -
Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86) Jul 9 2008 14:43:34 Copyright (c) 1988-2008 Microsoft Corporation Enterprise Edition on Windows NT 6.0 (Build 6001: Service Pack 1)