title: Can't connect to SQL Server 2008 from .NET 3.5
body: <p>I installed SQL Server 2008 Management Studio, and uninstalled 2005 as a consequence my .net application with  a local SQL Server express doesn’t work anymore. I tried with nothwind 2008 sample at my App_Data folder. The connection string is : </p>
  
  <pre><code>Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\NORTHWND.MDF;Integrated Security=True;User Instance=True
  </code></pre>
  
  <p>When I try to connect to the file and testing the connection I get the following error:</p>
  
  <blockquote>
    <p>A network-related or instance-specific
    error occurred while establishing a
    connection to SQL Server. The server
    was not found or was not accessible.
    Verify that the instance name is
    correct and that SQL Server is
    configured to allow remote
    connections. (provider: SQL Network
    Interfaces, error: 26 - Error Locating
    Server/Instance Specified)</p>
  </blockquote>
  
  <p>I verified the security setting of the file and put everyone full control. What setting should I update in order to be able to open 2008 version. Any help would be greatly appreciated. </p>