Wow, I'm not making any progress on this issue myself. I'm running a stock DELL XPS 12 convertible Windows 8 hybrid. I fail in the exact same way. I've tried updating all the drivers, bios, and many other system checks. Unplugged my only external devices,
etc., etc.
Still seems to be no solution from Microsoft and everything I reads sounds like Microsoft isn't being very proactive with a fix. You've got a lot of people on the forums offering to send debug logs but no apparent takers on Microsoft's side.
I don't want to do a clean install and loose the way my machine is configured. The last thing I'm working on is that sfc /scannow was returning and error but this may have happened during the failed 8.1 installs.
I ran
Dism /Online /Clean-Image /ScanHealth
and
Dism /Online /Clean-Image /RestoreHealth
Which correct component store corruption and now sfc /scannow works correctly.
I'm going to fully uninstall my Displaylink drivers and try the Windopws 8.1 update again but it will have to wait until Monday.