BOOLEAN
KeCancelTimer(
IN PKTIMER Timer
);
KeCancelTimer dequeues a timer object before the timer interval, if any was set, expires.
If the specified timer object is in the system timer queue, KeCancelTimer returns TRUE.
If the timer object is currently in the system timer queue, it is removed from the queue. If a DPC object is associated with the timer, it too is canceled. Otherwise, no operation is performed.
Callers of this routine must be running at IRQL <= DISPATCH_LEVEL.