Abstract: A desktop computer includes a main computer module, a power supply module and a connecting unit. The main computer module includes a housing and a plurality of electronic devices mounted in the housing. Each of the electronic devices has a power supply input. The housing is formed with a cable opening. The power supply module is disposed outside the housing of the main computer module, and has a plurality of power supplying outputs. The power supply module is operable so as to provide a plurality of dc operating voltages at the power supply outputs. The connecting unit includes a first cable portion, a second cable portion and a male-and-female electrical connector set. The first cable portion is disposed in the housing, and has a plurality of wires connected respectively to the power supply inputs of the electronic devices. The first cable portion extends outside the housing via the cable opening.