People cannot escape the fact that the world is becoming more and more dependent upon the use of Information and Communication Technology (ICT) and that Personal Computers (PCs) are one of the means. Recently, the demand of “Green Computing”, which represents an environmentally responsible way of reducing power consumption and involves various environmental issues such as waste management and greenhouse gases, is increasing explosively. The authors have laid great emphasis on the need to minimize power consumption and heat dissipation by computer systems, as well as the requirement for changing the current power scheme options in their Operating Systems (OSs).