The process status helper functions make it easier for you to obtain information about processes and device drivers running on Microsoft® Windows NT®. These functions are available in PSAPI.DLL, which is distributed in the Microsoft® Platform Software Development Kit (SDK). The same information is generally available through the performance data in the registry, but it is more difficult to get to it. For more information on performance data, see The Registry Interface. For information on Performance Data Helper (PDH), see The PDH Interface.