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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
This error message occurs when you are not able to contact the SQL Server.
There are several possible reasons for this:
1) SQL Server is not running.
2) There is a problem with your network connection.
3) You are connecting from a remote machine, and there is a firewall in the way.
4) You are connecting from a remote machine, and the network is segmented.
5) You are connecting from a remote machine, and the browser service is not running and you are trying to connect to the named instance.
6) You are connecting from a remote machine, but SQL Server does not accept local connections.
Please make sure that all network cables are properly connected.
If the problem persists, please contact your IT department regarding the SQL Server and/or network.
You could suggest that they open the SQL Server Configuration Manager and verify that TCP/IP and Named Pipes are enabled.
SQL Server and SQL Server Browser should also be added as exceptions in the firewall.