I have an installation of DNNN 5.6 with SQL Server Express 2005 on one development machine.  The database was created within visual studio and is a user instance.  I want to put this on another development machine.  I added the machine name of the second server and detached the db.  I then copied over the entire directory including the db which was in App_Data.  On new machine I attached the database and create the virtual directory.  They are both under localhost.  When I bring up the website, I get the installation page again with error message
Connection Error(s):
Index #: 0
Source: .Net SqlClient Data Provider
Class: 14
Number: 15382

Machine 1 is XP, machine 2 is Windows 7.    What else do I need to do to get this to transfer?

Attach is wrong word.  In VS I did detach the database on the old server.  On new server, in VS, I connected to that db, not attach (pardon, not used to SQL Express.  I never opened this in management studio).  However,  I now tried to just create a newdnn site on the new server (to determine if it was this server or my previous dnn app).  It gave the same message so it may have something to do with the new server and SQL Server Express.  What am I missing?

IIS AppPool\DefaultAppPool and Network Service has full access to database file. This is Windows 7. It gives following error message
Index #: 0
Source: .Net SqlClient Data Provider
Class: 14
Number: 15382

What else can I check or need to do?