I've installed SQL Server 2012 and visual studio express for web 2012, I found that I couldn't connect to SQL via asp.net. I installed another SQL Server 2012 instance and changed datasource to (LocalDB)/v11.0, it then works.

- But in the security configuration, though I've set the windows authentification,I get this error:
There was a problem with the selected datastore, which could be due to an invalid server name or credentials, or insufficient permissions. It may also be caused by the role manager feature not being enabled. Click the button below to redirect to a page where you can select a new data store.
The following messages may help diagnose the problem: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or cannot be reached. Verify that the instance name is correct and SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26-An error occurred while locating the specified server / instance)”
- After testing the provider for storing site management data:Aspnetsqlprovide ’connection with sql,another error happens:
Failed to establish database connection.
If you haven't created a SQL Server database, exit the site administration tool, use the aspnet_regsql command-line utility to create and configure the database, then return to this tool to set up the provider.

- Following the error message, I installed aspnetdb to this
(LocalDB)/v11.0, and changed the codes inmachine.config:
<connectionStrings>
<add name="LocalSqlServer"
connectionString="Data Source=(LocalDB)\v11.0;Initial Catalog=aspnetdb;Integrated Security=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
- I also set IIS connection strings as codes above and changed Application pool identity to“LocalSystem”,but these errors still occurs.
I really hope someone can help me to handle this, thanks