Cannot not connect to SQL Server instance.

Hello,

I have SQL Server 2012 installed and when I run this command:

sc query mssql$MSSQLSERVER

I get this error:

[SC] EnumQueryServicesStatus:OpenService FAILED 1060:
The specified service does not exist as an installed service.

I run this command on the same server where SQL Server is installed.  Databases are on the same server too.  TCP/IP is enabled for the instance and port 1433 is open on the server's firewall. SQL Server Browser is running.

Many errors in the SQL Server error logs like:

SQLServer Error: 11001, A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct.

SQLServer Error: 11001, TCP Provider: No such host is known. [SQLSTATE 08001]

Any ideas what could  have gone wrong?

Thanks,

Paul

Paul