Vista is more modular (I Am Back)
Vista is a completely modular operating system: security updates, language packs, and service packs are simply components which can be added on to the basic Vista image. For deployment of these components over your enterprise, tools such as the Package Manager can be used. Before you deploy Vista, you need to configure which of the components to install; this is done by enabling the components as required, using a tool such as the Windows System Image Manager.
Vista can be patched before it is deployed on to your network. This is another benefit of having a componentised image–you can apply changes and service the image file both online and even offline when Vista is not running.
Since drivers are also treated as components under Vista; they too can be added and removed easily. This means that driver updates or new drivers can be pushed just-in-time into the OS image, when the machine boots for the first time.