If you have looked at your WSUS (Windows Server Update Services) server lately should have seen a new product category named OOBE ZDP but you likely have no idea what it is… and neither did I until I asked Partner Support. After two weeks of research this is what they came up with:
OOBE ZDP was designed to allow “must have” updates to be installed during OOBE, before the user reaches the Start Screen. These updates are meant to fix security holes and functional issues that block core experiences in Blue as early as possible. IDP driver and firmware updates can also be delivered through this mechanism. This update mechanism should *not* be confused with the GDR-DU process (store upgrade)
OOBE ZDP update should not require more than one reboot. The combined size of all available OOBE ZDP updates should be less than 5MB. The combined install time of all OOBE ZDP should be less than 4 minutes.