When opening the SQL Server Configuration manager (for SQL Server 2008 R2 in my case), I kept getting following 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]

The solution to resolve this turned out to be quite simple. Just open a command prompt and execute following command:

C:\Program Files\Microsoft SQL Server\100\Shared>mofcomp “C:\Program Files\Microsoft SQL Server\100\Shared\sqlmgmproviderxpsp2up.mof”

Depending on the SQL version installed the path to the file could also be something like C:\Program Files\Microsoft SQL Server\90\Shared\sqlmgmproviderxpsp2up.mof