Hi, I having the same problems. The update seems to be unable to install properly before the computer shuts down completely. And when I switch on my computer again, the same error message appears which says that it is undoing the updates and it refreshed and the same error messaged popped out again before my log in page can come on.
I have done a check on my update history and this is what I have found out with regards to the error code: Failed to install update for Windows 8.1 for x64-based systems KB2975719.
I believe the problem will still persist and the same error cycle will still occur every time when I shut down from now on. Please advice me on what I should do. My computer is a very new one and its operating under Windows 8.1.