Lately I've been seeing one particular svchost.exe sucking CPU. There always a number of in-proc running inside of each of the many svchost (Service Host) instances. Using ProcEx, I figured out the PID of the specific instance. Then, I right clicked within ProcEx, hit Properties, and under the Threads tab noticed that wbemcore.dll was working REALLY hard.

Crap, time to re-schmutz WMI's repository. So, I stop WMI from the command line with :

net stop winmgmt

Then I deleted the Repository directory in c:\windows\system32\wbem\ then started again with

net start winmgmt

Then I re-stored/compiled all the .mof (Managed Object Format) files with a batch file containing this one line:

for %%i in (*.mof,*.mfl) do Mofcomp.exe %%i

Now I'm back in business.