If you ever wanted to know what version of Microsoft SQL Server and Edition you are running then Microsoft is maintaining really nice knowledgebase on this subject.
http://support.microsoft.com/kb/321185
For SQL Server 2000 and later, use following SQL query to check the version and edition..
SELECT SERVERPROPERTY(‘productversion’) as Version, SERVERPROPERTY (‘productlevel’) as SP, SERVERPROPERTY (‘edition’) as Edition
For SQL Server 7.0 and earliar, use following SQL query to check the version. Please note that do not use this command on the SQL Server 2000 and later. It may return the information but may incorrect at times.
SELECT @@VERSION
Look at the Microsoft KB article for more detailed information.
Nik