The stabilization and destabilization of water-in-oil (w/o) microemulsion under varied amounts of surfactant and water and varied temperature by mixing with butan-1-ol and isopropyl myristate have been studied in detail. The surfactants used were sodium dodecyl sulfate, cetyl trimethyl ammonium bromide, and cetyl pyridinium chloride. The distribution of cosurfactant (butan-1-ol) between the interface and the oil at the threshold level of stability has been examined, and the thermodynamics of the transfer process of the cosurfactant from the oil to the interface have been evaluated. The structural parameters (dimension, population density, and water pool radius) of the dispersed water droplets in the oil phase have been also evaluated along with the examination of the interfacial population of surfactant and cosurfactant. A rational analysis of the results has been attempted.