Sometime before I faced different kind of issue on one of staging SQL Server. I required to change the TCP port of an instance where multiple instance were running, I just open compmgmt.msc and connected SQLServer Configuration Manager , then I started receiving 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 class [0x80041010], SQL Server Cannot Connect to WMI Provider permissions or server is unreachable. ” This may caused by an issue with the compiled SQL Configuration Manager GUI’s communication with WMI. If we have multiple instance running on SQL Server on a single windows server or we have un-installed any instances then this kind of issues we may face to connect.