A "carbon footprint" is the "total set of greenhouse gas emissions caused directly and indirectly by an (individual, event, organization, and product) expressed as CO2" emissions. Since CO2 emissions are indicative of energy use, the higher the associated CO2 emissions, typically the greater the associated costs. A typical desktop PC system includes the computer (desktop or laptop), monitor, and printer. A desktop computer might need 65-250 watts of electric power when in use, and a color monitor, another 40-150 watts. A laser printer can need as much as 400 watts or more when printing, although considerably less if in standby mode. Ink-jet printers can use 12-30 watts while printing, but less than 5 watts while turned on but sitting idle. The more computers on campus, the higher the incentive to investigate potential cost savings by reducing their power consumption. Institutions of higher education (IHEs) can decrease their carbon footprints and save money when they embark on energy-saving programs at the desktop. Efforts to reduce the energy consumption associated with personal computers are often referred to as "green computing," which is the practice of using computing resources efficiently and in an environmentally sensitive manner. Many institutions have chosen to include information on their websites about green computing efforts and how to reduce carbon footprints. This article discusses three ways that individuals and institutions can decrease energy use with personal computers: (1) Power management of desktop computer systems. Power management helps to manage the power supply to a desktop computer so that it minimizes the power consumption of the computer without affecting the quantity and quality of the work done; (2) E-mail practices and policies. Computer users can use e-mail to reduce energy consumption by sending e-mail memos instead of paper ones; and (3) Online learning options. Online learning options using learning management systems and web/videoconferencing can cut back on the need for traditional physical classrooms (and other infrastructure) while also reducing travel costs and associated energy use. Such energy- and cost-saving measures can decrease an institution's energy footprint and energy costs. (Contains 5 figures and 32 endnotes.)