Hi Dmitry,

You can have one default instance and multiple named instances on PC. The default instance is referenced by PC name. The named instaneses - by < PC name >\< Instance Name >. Assuming that you use defaults during installations, than Dev edition would be default one and Express the named one. Theoretically, nothing prevents you from installing Express as default instance and dev as named instance SQLEXPRESS, though. :)
Check http://www.berezniker.com/content/pages/sql/microsoft-sql-server/retrieving-sql-server-edition-version-and-service-pack-info


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>When I bring up my SSMS I have two choices in the Server Name drop down. One (default) is simple the name of my PC (MYPCNAME). And the other one is MYPCNAME\SQLEXPRESS. When I select the name MYPCNAME or MYPCNAME\SQLEXPRESS the version shown in SSMS is the same (9.0.1399). Does it mean that I have two instances of the SQL Server 2005? Or I have SQL Server 2005 Developer Edition and SQL Server 2005 Express (both of the same version)?
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>TIA.