Can't see database listed in SQL Server Import and Export Wizard

(MSSQL newbie alert) I have a number of databases on my machine, some were created using aspnet_regsql, others downloaded from the microsoft ASP.NET MVC 2 tutorials (e.g. http://www.asp.net/mvc/tutorials/mvc-music-store-part-3). The db's created with aspnet_reg开发者_如何学编程sql are listed in the wizard dropdown, but the ones I downloaded are not. I tried copying the downloaded mdf's to C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA (where the "good" files are) and restarting the sql server services (both SQL Server (SQLEXPRESS) and SQL Server Browser (SQLEXPRESS), but not luck. The downloaded files also fail to appear on the list that gets populated in the MySQL Migration Toolkit. Strangely, I can used the "invisible" mdf's in the VS2010 web apps created via the tutorials.

It's not enough to just copy the MDF file to a directory. The database has to be attached. See How to: Attach a Database File to SQL Server Express