Cannot connect to SQL Server from Management Studio (both 2012) I installed SQL Server 2012 Express. It seems to be running fine. My SQL Server Configuration Manager looks like this:


  


From what I understand it means that my instance is called MSSQLSERVER.

Now in Management Studio when I try to log in it can't find the instance. I've tried .\MSSQLSERVER but it doesn't work:


  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: SQL Network Interfaces, error: 25 - Connection string is not valid) (Microsoft SQL Server, Error: 87)


I don't understand what I'm doing wrong. Why can't I connect to the server?
With a default instance,  specify only the host name when connecting.  As a shorthand when connecting locally, specify only ..