Multiple reports that the Feb Cumulative Update for Win10 (1903? 1909?) resets the desktop -- custom icons missing, background set to Windows logo -- and would not recognize the established logon account. Are you seeing the same? https://t.co/uZTcRqeEMN
— Woody Leonhard (@AskWoody) February 12, 2020
Be that as it may, it comes as little consolation to users who are affected by whatever bug the update is introducing.
"Just installed the latest Feb 2020 Windows 10 updates. Upon completion it appears to have reset the display to default windows system. That is, all custom icons missing, background returned to windows logo, would not recognize my logon, set a temp logon," a user wrote on Microsoft's support forums.
There is a fix that involves mucking around in the Registry, though users should be expected to do that—you can break things by altering Registry settings. Some users report success having their settings restored by restarting Windows 10 several times. We suggest giving that a try if you are affected by this. Otherwise, you can uninstall the KB4532693 until Microsoft gets a handle on things.