As you can't have failed to notice, the big Anniversary Update for Windows 10 began rolling out yesterday, but some users have hit problems either installing the upgrade, or with Cortana post-upgrade.
There have been complaints posted on the Microsoft community message boards noting unhelpful error messages which are popping up when some users are attempting to install the update.
Folks are getting various codes spewed at them when the installation fails to fire up, and as Softpedia reports the most commonly seen ones are 0x80070057 and 0xa0000400. Which obviously tells you nothing about exactly what's gone wrong here.
This problem apparently affects at least some Windows 10 Home and Pro users, and some of them appear to be stumped by it – although updating via the Media Creation Tool instead (rather than Windows Update) has apparently been a successful workaround for others (using the 'Upgrade this PC now' option).
So that might be worth a shot.
Another problem is happening to Windows 10 users who have successfully installed the upgrade, only to find that Cortana has been banished from their system.
One Microsoft community forum denizen posted (opens in new tab) that: "Cortana worked perfectly before AU [Anniversary Update], but after AU it just disappeared. All Cortana settings are missing."
And others replied that they faced the same issue, plus we've seen further complaints elsewhere on the net about Cortana being ditched by the update.
It would seem that these flaws are hitting a limited number of Windows 10 users, but of course it's frustrating if you happen to be one of the minority. Needless to say, though, given the scale of this update, there was always likely to be a glitch or two in the system.