The word "de-activating" refers to the process of ceasing or stopping the operation of something. Some of the antonyms for de-activating are activating, enabling, empowering, energizing, engaging, and starting. These words bring back the energy, force, or momentum back into the system that was previously stopped. Activating any device or system means to bring it into action or operational mode. Enabling refers to giving someone or something the necessary resources, capability, or power to perform a certain task. Empowering means giving someone the authority to make decisions or take actions. Hence these antonyms create a sense of positivity and energy, bringing life back into the dull, stagnant, or dormant system.