How to check if WMI is broken or not?
Solution 1:
or just do somethig like this at an elevated prompt
wmic os
Solution 2:
WMIDiag is a good place to start.
WMI Diagnosis Utility
http://technet.microsoft.com/en-us/library/ff404265.aspx
WMIDiag download
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=7684