Summary: Use Windows PowerShell to find the key of a WMI class.

 How can I use Windows PowerShell to discover the property that has the key qualifier for a WMI class?  

 Use Get-CimClass and iterate through the properties:

$class = Get-CimClass -ClassName Win32_Process

foreach ($property in $class.CimClassProperties) {

 $property | select -ExpandProperty Qualifiers |

 foreach {

   if ($_.Name -eq ‘key’){

     $property

   }

 }

 }