John,

The link to the tutorial for Windows Management Instrumentation (WMI) is 
as follows:

http://msdn.microsoft.com/downloads/default.asp?URL=/code/sample.asp?
url=/msdn-files/027/001/574/msdncompositedoc.xml

Sorry it is so long but that's MS for you. This should give you all you 
ever wanted to know and then some.

Happy coding,

Tracy