Renaming a database will not change the names of the files associated with the database, including the .MDF file. What gets changed is the database name that the Server displays. For example, suppose you take database file Samples.mdf, and attach it as Samples. If you then use the Rename function and rename it as Samples1, the database name will be displayed as Samples1 in System Architect, SAEM, or in Microsoft SQL Server Enterprise Manager, but the original file that you attached, Samples.mdf, remains unchanged.