---EDIT: Default WDS settings (Properties, Boot) dictate you have to hit F12 (quickly) to continue booting, otherwise you will get PXE Boot Aborted. I am sure this is designed so that a boot order with NIC/PXE 1st will still boot to local devices without user intervention
WDS log (Source Deployment-Services-Diagnostics, Event ID 57347) advised: The PXE server processed a request from a client of architecture x86. However there were no boot images installed for this architecture
It seems either my NIC/PXE-code or BIOS is providing an invalid response to the architecture. Maybe its based on the processor on the NIC, I am not an engineer so I can't say for certain. However per microsoft:
Each computer that will be booting from the network should have DHCP option 93 to indicate the client’s architecture. This enables a PXE server to know (at boot time) the exact architecture of the client from the first network boot packet. On many x64-based computers, the architecture value either is not set or is not set to the expected value. Generally, this means that the architecture is specified as x86-based but the computer is x64-based
This article refers to a System Center component, however if you search for x86 (the 6th iteration) it advises you should have a x86 and x64 boot image. I guess you can FORCE it to boot a x64 (this may cause you trouble in the future) by opening WDS, right-clicking server, Properties, Boot tab