Você não precisa fazer isso. O Vista e o mais novo, por padrão, mantêm um cache de todos os recursos no disco rígido, portanto, você nunca deve precisar da mídia de instalação do sistema operacional.
De Engenharia do Windows 7: Espaço em disco :
As you might notice today in Windows, when you choose to add a feature that was not installed Windows does not require a source (a DVD or network location). This is because the feature is stashed away as part of a complete Windows install—this is itself a feature. We will always keep features available and will always service them even when components are not installed—that way if you add a component later you do not risk adding a piece of code that might have been exploited earlier.