title: MDF files are missing extensions
body: <p>I have restored 4 databases into my new SQL 2008 R2 Server.
  Two databases came from a SQL 2000 Backup, the other two from SQL 2005.
  How come when I look at the folder where the Row Data files are stored and also look at the Database Properties under files, the 2000 database files have MDF extensions with the type SQL Database Primary Data File, and the ones that came from 2005 have no extensions with the type "File"?</p>
  
  <p>All databases are working properly.</p>