Yesterday (4/5/2017), I successfully upgraded Windows 10 on two computers, but on my office desktop, it failed. It generated Windows Update error 0xc1900204 when trying to update from version 1607, OS build 14393.693. Searching for help on this error generated a number of pages relating to the Windows 10 preview or upgrading from Windows 7 to Windows 10, but I see nothing related to the newest upgrade. If anyone can point me to a discussion or web page that addresses this issue, please let me know.
LTR