Return Codes

Code Description
WHLLOK The PS is uninhibited and ready for input.
WHLLNOTCONNECTED Your WinHLLAPI application is not connected to a valid host session.
WHLLPSBUSY Function timed out while still inhibited.
WHLLNHIBITED The PS is inhibited.
SHLLSYSERROR The function failed due to a system error.
WHLLCANCEL The asynchronous function was cancelled.