Performance Libraries and WMI
WMIPerfClass and WMIPerfInst Providers
WMIPerfClass Provider creates WMI Performance Counter Classes at system initialization. The WMIPerfInst Provider dynamically provides performance counter data for these classes. The WMIPerfClass Provider provider supplies classes for both version 1 and version 2 Performance Counters.
Version 1 counters are found in the registry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services. Services that provide performance data have a Performance subkey. WMI performance classes created from version 1 counters do not have "Counters" as part of their name.
The GUIDs identifying a version 2 performance counter provider are found in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib\_V2Providers.
WMIPerfClass is registered as a normal WMI class provider. WMIPerfInst is a WMI instance provider that supplies data from Performance Data Helper (PDH) for both version 1 and version 2 counters. For more information, see Using the PDH Functions to Consume Counter Data.