It seems Windows 10 Update fails sometimes, especially with the Fall Creators Update. It continuously wants to install, you approve, it runs, and fails, often with error code 0xc1900208.
In troubleshooting I have found most of the time it will install if you click the “Update now” button form the Creators Update Web page. It seems to check for compatibility, make any adjustments, then Install.https://www.microsoft.com/en-us/software-download/windows10
Should that fail to work, you can download the Windows 10 Update Troubleshooter, which will troubleshoot, and offer to repair any issues found. There is also a troubleshooter for Win 7 and 8.https://support.microsoft.com/en-us/help/4027322/windows-update-troubleshooter
However, I also recently read about an issue with attached USB drives oddly causing the update to fail. Recently, on a PC on which I tried all of the aforementioned options, and had no attached USB devices, I discovered a DVD in the drive. Once ejected the update installed without a problem. This strikes me as very bizarre, but perhaps the update searches other available drives for some reason.
Therefore; I recommend if having issues with Windows updates, try disconnecting any USB devices such as external drives, thumb drives, phones which may be charging, and possibly even USB printers, and don’t forget to check the DVD tray, just in case.