After the MediaCreationTool repeatedly failed to run at all on either my Win 7 64 Pro or 8.1 Home devices, I decided to just wait for the update. Now it turns out that it's tried 15 times or more, and failed every time, with this error, 80070005.
I searched here for "80070005, and came up empty, and then googled it. I have spent the last hour or more reading various articles, suggestions, etc, and just wondered if anyone here had a clear, concise summary of the steps I should take to try to fix this problem. As with the MediaCreationTool failure, this error is happening on my machines.