"OEM Preinstallation Kit" is very helpful and handy tool to system builders, enterprises or Small organizations who involved in redistributing the PCs in the condition of ready or distribute condition. This kit might be very useful to System builders who are involved in distributing or reselling of the server or Desktops with pre-installed operating system and applications with customization settings.The OPK is a set of tools and documentation that help you automate Installation Operating system, installation of custom / SOE applications and applying custom settings to your server or desktop builds.
Below link Microsoft link would help you to guide A to Z of Windows 7 OPK
Below link Microsoft link would help you to guide A to Z of Windows 7 OPK