While opening of SQL Server Configuration Manager if you get error message of
"Cannot connect to WMI provider. You do not have permission or the server is unreachable"
This problem occurs because the WMI provider is removed when you uninstall an instance of SQL Server 2008. The 32-bit instance and the 64-bit instance of SQL Server 2008 share the same WMI configuration file. This file is located in the %programfiles(x86)% folder.
To work around this problem, type the following command, and then press ENTER:
mofcomp "%programfiles(x86)%\Microsoft\Microsoft SQL Server\100\Shared\sqlmgmproviderxpsp2up.mof"
Refer the KB# 956013