To start off this is only happening on our Laptops not desktops, they image just fine.
(laptop is a Dell Lattitude 7470 with win7 64bit pro)
When PXE booting the laptop they will load the Boot Image without issue:
But will fail with the DHCP service on the following screen:
My first thought was the Nic Drivers, so i disabled the Wnic and downloaded the lastest drivers from the manufacture website (Link to drivers) and rebuilt the boot image with these drivers, the Win8 and up nic drivers were already in the boot image however, i added the win7 drivers for good mesure but that failed to work.
Again the exact same cable works just fine on the desktops, its just these laptops.
Let me know any other additional information i can provide that will help.