This work is devoted to investigating the current nonlinear distortion of IT devices linear and switching mode power supplies. A new developed software package is shown suitable for separate varying degrees load of functional parts of personal computers. Based on the collected voltage and current harmonic analysis serious distortion is stated in current time functions in automatic power factor compensating devices, too. Enormous distortions are observed in simple structure power supplies low power consumption consumer electronic devices. The consequences and effects of this behavior is described, and possible solutions are adumbrated in detailed conclusion with integration of domestic size complex energetic systems consisting of renewable energy sources, battery storage and single and three phase current inverter parts, especially in development of direct current bus systems in computer system applications.