x86 has always been favored as the base for AIO projects. I at this moment decided eff that. EFI is everywhere now and x86 is not really necessary anymore as x64 works well and the majority of systems have x64 capable cpus. People are used to having to add the bootx64.wim to the BCD, and they usually don't have the x64 setup\upgrade files in favor of the x86 ones. I can't remember the last time i had to upgrade an x86 machine. Plus, with EFI, they now have to totally re-route the bcd entries to point to the bootx64.wim rather than the default boot.wim. Its all ass backwards. For a DVD\USB AIO base use the x64 DVD in its entirety, and substitute the x86 iso \boot dir for max MBR\x86 support. Add the x86 boot.wim as \sources\bootx86.wim and only change the \boot\bcd adding a reference for bootx86.wim. This way you don't have to altar the EFI bcd as x86 is useless. Make an AIO install.wim. To install from x86, run in WinPE x:\sources\set86.exe (renamed setup.exe) and have a copy of that in the DVD sources folder. Done. Thats a minimal changes AIO in my opinion with full functionality besides x86 upgrades.