BOOLEAN
KeCancelTimer(
  IN  PKTIMER Timer
  );

Routine Description:

    This function cancels a timer that was previously set to expire at
    a specified time. If the timer is not currently set, then no operation
    is performed. Canceling a timer does not set the state of the timer to
    Signaled.

Arguments:

    Timer - Supplies a pointer to a dispatcher object of type timer.

Return Value:

    A boolean value of TRUE is returned if the the specified timer was
    currently set. Else a value of FALSE is returned.