SQL Sever database server name issues

Purpose: Resolves a situation where the database server name is unknown .
Error: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or could not be accessed. Verify that the instance name is correct, and that SQL Server is configured to allow remote connections. (Provider:sql network interface, error: 26-Error locating the specified server/instance)

The database connection string is typically: computer name \ Instance name, the instance name is unknown when opening SQL Sever Configuration Manager view SQL Sever Service red circle is the instance names of the database

Workaround: Open SQL Sever configuretion Managert, select Mssqlsever protocol in SQL Sever network configuration, enable named Pipes and TCP/IP, Login successful using the original link string, the sa account password for SQL Sever authentication is 123 Error: "SQL Sever 2008 Remote debugging failed" error occurred in SQL Sever service under SQL Sever 2008r2 Configuration Manager Workaround: This is due to a file compatibility issue with the sql2012 part of the default installation after installing VS2012, and the Control Panel uninstall Microsoft SQL Server Expres 2012LocalDB is resolved.

Note: Sometimes not connected to the database may be the current account is not owned by the database login rights, you can first login to the SQL Sever account via the Administrator account