How to find the version of SQL installed
Launch SQL Server 2005 Configuration Manager from Microsoft SQL Server 2005 à Configuration Tools menu. Click on SQL Server 2005 Services and the right pane will be refreshed with all the services installed as part of your SQL Server installation. Right click on the SQL Server (MSSQLSERVER) for default instance or SQL Server (instancename) for named instances and go to Properties. Click on Advanced Tab. Look for Version (for SQL 2005 RTM, this should read 9.00.1399.06) and Stock Keeping Unit Name (this is the edition of SQL 2005 - Standard or Enterprise etc.) to find the build and edition of SQL 2005 respectively.