A componentized operating system is separated into multiple different components. In certain embodiments, a bill of materials (BOM) identifies at least one component that is installed (or is to be installed) for an operating system image on a computer. Each component includes one or more files and has a corresponding manifest that identifies which other components (if any) the component is dependent on. During an installation or upgrading process, the manifest for a component can be accessed to determine which additional components (if any) are to be installed even if they are not explicitly identified in the BOM.