The present invention relates to systems and methods for providing a universal computing system. Implementations include a modular motherboard having two or more electronic circuit boards that are connected to form a motherboard. The two or more electronic circuit boards each include a security key structure on a connector for providing a keyed connector therebetween. Computing components may be provided on two of the major surfaces of the first electronic circuit board circuit board. Components are disclosed in which the computing system will not turn on unless the first printed circuit board is electrically connected to the second printed circuit board. A heat sink is disclosed that may be used in the universal computing system. A customizable encasement is disclosed. An expandable memory device is disclosed.