There are three certainties in life: death, taxes and duff patches from Microsoft. So, yes, some Windows 10 users have found their PC unhappy following Tuesday's patch shenanigans.
A helpful forum posting from one of Microsoft's loyal MVPs concerning the arrival of KB4532693 for Windows 10 1903 and 1909, and KB4532691 for 1809, has seen some customers reporting that the updates had left their systems a little distressed.
Users have found things reset to a seemingly default state and a temporary user account used for login, the desktop and taskbar shorn of icons, keyboard layouts changed, applications (such as Firefox) not working, and Windows 10 keen to have a user set up their profiles again.
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It sounds suspiciously like, for some users, the update somehow restarted Windows 10 using a temporary account, which naturally lacks the settings locked away with the user's profile.
The Microsoft forum is the usual car crash. Some users have found that a few restarts will restore their PCs to working order. Others have opted to uninstall the offending update and put a hold on receiving any more for as long as possible. A potentially risky approach, since there are some important fixes in the patch, but understandable when faced with the borked computer.
Reddit also has its fair share of users complaining about the update. One running Windows 10 1809 reported that the patch "messed up almost everything about my PC".
Microsoft has remained tight-lipped on what might be happening, with the support article for the 1903 and 1909 update warning of issues around Windows Server Container images, but otherwise the update was expected to improve "the installation experience when updating to Windows 10, version 1903" and security.
Shovelling a user's profile off into the recesses of the hard disk is one way of securing things. If you can't access your apps and data, presumably nobody can.
We will update this piece when Microsoft responds to our request for comment. In the meantime, as 1809 prepares to go gentle into that good night as far most users are concerned, it is reassuring to know that the later versions are still seemingly possessed of an ability to make user profiles magically disappear. ®