A client-server network environment is temporarily transformed into a grid computing environment through the deployment of a network-booted grid operating system to each of a plurality of network clients. Each participating client operates in the client-server mode under a local operating system. At an appropriate time, a server transmits to each client a thin-client boot image (a dynamically built customized image or an image obtained from a store of predefined boot images) along with a grid application for which the thin-client has been optimized for peak performance. Each client re-boots using the thin-client image, thereby entering the grid mode and allowing substantially all of its computing resources to be dedicated to executing the grid application. At a later time, the server directs that each client terminate the grid application and re-boot in its respective local operating system, reverting again to the client-server mode.