When WMI is throwing errors you can get it repaired with the steps mentioned below. sometime WMI issue occur when SP is instlled or some major security update.
Try to rebuild the repository…..
1. winmgmt /clearadap
2. winmgmt /kill
3. winmgmt /unregserver
4. winmgmt /regserver
5. winmgmt /resyncperf
6. net stop winmgmt
7. del %SystemRoot%\system32\Wbem\Repository\*.* /s
8. net start winmgmt
9. %SystemRoot%\system32\wbem\wbemtest.exe
10. Connecting using Root/Default
first time connection will take some time since the repository is being rebuilt.