Previously mentioned "SMSC LAN9500 USB 2.0 to Ethernet 10/100 NIC" has been found capable of doing a UEFI PXE boot! BUT there is a problem. Server 2008 R2 gets the arch value from the NIC and reports it as 7. Now it is already known that Server 2008 R2 does NOT support UEFI PXE boot, but seems to understand what to do with Arch 7. So it ends up serving out the Itanium EFI boot option (bootmgfw.efi) to the NIC. While this appears to work, the PE is loaded with the Itanium EFI rom and the actual hardware is using UEFI. The expected result (as with BIOS based PXE boot to UEFI/GPT systems) is that BCDBoot is unable to write to the BCD Store. Interestingly enough, if you disable the UEFI Boot option in the BIOS, it automatically will disable the onboard NIC and boot ROM. It does not appear that this system is capable of doing a BIOS level PXE boot. Even if you enable the LAN Option ROM, the other networking related pages in the BIOS are unavailable (grayed out) and it won't even attempt to boot from LAN even if you set LAN as the first boot item and disable everything else. This NIC is included in the CZC U116T Ultrabook. Unfortunately, this product is out the door, so while I have built a new system with Server 2012, I won't be able to test this functionality until another one comes in or something else shows up that can do a UEFI PXE boot.