Abstract: A method for hierarchical product selection and purchasing from a server. The method includes accessing a plurality of products from a plurality of component subareas, wherein the products are for an assembly of a computer system, and wherein each of the component subareas have corresponding compatibility constraints with respect to other component subareas. A hierarchical presentation of the products is generated, wherein the presentation proceeds from a parent product out of the plurality of products to a child product out of the plurality of products. The hierarchical presentation of the products are provided to a client computer system via a Web browser hosted on the client computer system, wherein the presentation is configured to show child component subareas that satisfy compatibility restraints with parent component subareas. An order for the at least one product is accepted and implemented with a corresponding e-commerce agent for the product.