After several attempts to install the public release of 8.1, I have the same crash at "setting up a few more things" 54% - then the "Sorry we could not complete the update error. 0X80070004-0X400D
I have cleared the cashe, disabled anti virus... no luck. This is Windows 8 Pro with the Media Center add-on and I am wondering if this is the problem? Since it got most of the what through, perhaps another clue is crash at 54%??