Sql Server Express And App_Data

Hello

I have installed SQL Express on my computer, in a named instance (called Demo).

I have done my connection and my web site using this instance. So I updated my web.config file like this



<connectionStrings>

<clear/>

<add name="DemoDb" connectionString="Data Source=localhostdemo;Initial Catalog=DemoDb;Persist Security Info=True;User ID=sa;Password=sa;Pooling=False" providerName="System.Data.SqlClient"/>

</connectionStrings>

And this is working perfectly well. Now I would like to do the same thing but use an attached mdf file to my web site.

So I try to add a new DB in APP_DATA and I have the error 40 (Shared memory provider - Could not open a connection to Sql Server).

Note that I was having previously the error 26 that "disappeared" when I updated my Sql Express connection to start the Sql Browser and to allow remote connections.



Any Ideas ?

Thanks,