Recently many kinds of power transducers have been commercially used to increase the energy efficiency. However, those devices unavoidably produce the harmonics having an integral frequency of fundamental waves. The harmonics should be removed since they have negative effects on the other devices based on fundamental sine waves. As the current information technology makes the PCs more widespread, it is essential to study the harmonics that they produce. In this paper the harmonic generation of a PC has been measured and analyzed. Additionally, the most efficient way of reducing the harmonics has been proposed.