User Instance in a connection string gives an error
<p>When program is trying to open the database I get:</p>

<p>Error message: Cannot open database "Chinatowndb" requested by the login. The login failed.
Login failed for user 'Lee-VAIO\Lee'.</p>

<p>Code is for connection string: </p>

<p><code>conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=Chinatowndb;Integrated Security=True;User Instance=True");</code></p>

<p>If I change the code to: </p>

<p><code>conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=Chinatowndb;Integrated Security=True");</code></p>

<p>It works.  Now I have another program that uses the first connection string, different database, and it works.  Note that the another program has the .mdf file with the App_Data folder.  Chinatowndb.mdf is store at C:\Program Files\Microsoft SQL Server\MSSQL10_50.SQLEXPRESS\MSSQL\DATA.</p>

<p>Why the error?</p>
