In one embodiment, the present invention includes a method for executing an application to perform voice over Internet protocol telephony, requesting a hardware key from a line interface device, comparing the hardware key to a software key associated with the application, and enabling the VoIP telephony if the keys match. In one embodiment, such a method includes detecting an aborted thread at runtime and determining whether the aborted thread is an oldest aborted thread. A ratchet arrangement joins the end faces of the adjacent windings with respect to the longitudinal axis of the support coil. Also included are a first primary game presented on a first primary game display and a second primary game presented on a second primary game display. Moreover, the emergency lighting system is configured to reduce an amount of power provided from a battery to the one or more emergency lights when an emergency condition is determined in order to maximize a battery life of the system. A rotating brush is provided for removing dust trapped on a filter arranged on an inlet side of an indoor fan.