On one computer, installed the first time, although I did have to reboot to get Search to work.
On my computer, I thought it was installed yesterday, as Notifications said that updates were installed, so I did not click on that, only to find a new notification today that updates were available. Checked, found that yesterday's supposed install had failed.
I have now tried to install the update four times today; each time, I get the screen that `Windows is getting ready to install updates, quickly followed by a restart, and the the pathetic 'Could not complete the update', and soon enough the lock screen appears. No error messages of any sort; both computers have the same Avast! anti-virus setup, so I don't believe that is the problem. I wonder if I ought to disable Avast! and try again.
Finally, after attempt number four, Notifications changed from claiming that updates were installed to informing that in fact there was a failure. Now the update won't even try to download again.