A computing device is configured to assemble and boot an operating system in stages. A primary boot image is first obtained that includes enough of the operating system to support basic networking. Once the primary boot image is obtained, either through download or from storage on the device, the primary boot image is booted to start the networking. Once the networking is active, the boot activity for the device is suspended and one or more secondary operating system images are downloaded by the device. These images are chained to the primary boot image thereby creating a single/cohesive operating system. These secondary operating system images are successively booted in “stages” with each successive stage building upon the functionality of the previous stage.