For finding the server name I opened SQL Server Configuration Manager but I am getting an error - what should I do?

I get this error:

Cannot connect to WMI provider. You do not have permission or the server is unreachable. Note that you can only manage SQL Server 2005 and later servers with SQL Server Configuration Manager. Invalid namespace [0x8004100e]

To find the server name, I opened SQL Server Configuration Manager, but I get this error mentioned above. What should I do?

I am a beginner at SQL Server - please help me with this.