Hey Guys, Long time lurker thought i would leave this here for someone to find. We have a client that wants windows 8.1 installed but have noticed the limited support for SCCM 2012 and certain drivers.
My issue was the Task sequence would complete successfully (with long driver loads, hp supplies 1.5GB of drivers) but would fail with the error ""Windows could not parse or process the unattended..." it was on the windows 8.1 boot screen. To the best of my knowledge what would happen is the drivers would load but then reboot the system in the middle of the windows setup. and then set a flag off in the registry that the system shutdown unexpectedly, but you cannot hit 'shift F10' to access command at that point in 8.1. So it would continue to error out and not proceed with install. Oh and also the I217 intel NIC driver is not packaged into the X64 boot image, you can find that in on this site.
My solution was to eventually put a minimalistic image into production and later attach the 9 drivers needed via DPINST.exe (found here). This worked pretty well with the image being able to deploy and drivers still being applied.
TLDR: Some drivers will cause unwanted reboots and cause your install to fail.
Computers in question
HP ProBook 650 G1