[edwr]

edwr, did you install windows 8 in legacy mode or UEFI?

UEFI. I've since installed Windows 7 in legacy mode, though ethernet and wifi didn't work, and I can't get the Windows 8 drivers to install, so now I'm reinstalling Windows 8.1 until that gets sorted out. Using legacy mode this time, seems to be working

edit: I forgot that someone mentioned hdmi audio not working with legacy mode turned on. It is indeed not working. So, back to UEFI. On the subject of things not working, pulling out usb drives from the 3.0 slot occasionally makes the system power off immediately (!), the usb xhci setting in the bios keeps resetting to disabled (may be related to previous), and the boot options menu just displays an unusable white screen. So, still a lot of work to be done, clearly