Provider: Named pipe provider, ERROR:40-Unable to open connection to SQL Server

An error occurred while connecting to the server. When you connect to SQL Server 2005, SQL Server does not allow remote connections under the default settings, which can cause this failure. (provider: Named pipe provider, ERROR:40-Unable to open connection to SQL Server) Description: An unhandled exception occurred during the execution of the current WEB request. Check the stack trace information For more information about the error and the source of the error in your code.

Exception Details: System.Data.SqlClient.SqlException: An error occurred while establishing a connection to the server. When you connect to SQL Server 2005, SQL Server does not allow remote connections under the default settings, which can cause this failure. (provider: Named pipe provider, ERROR:40-Unable to open connection to SQL Server)

I haven't run SQL Server for a long time, and today made a stupid mistake:

is no start service, haha do not laugh, open the service command is:net start mssqlserver ; The Shutdown service is:net stop mssqlserver

Provider: Named pipe provider, ERROR:40-Unable to open connection to SQL Server