Hi,
Open the classic Control Panel and access the File History page.
Click Turn off.
Right-click Start, and click Run:
Type the following folder path and click OK.
%LocalAppData%\Microsoft\Windows\FileHistory
Rename Configuration to Configuration.OLD
Rename Data to Data.OLD
This resets the File History configuration. Your previously backed-up data (on the external hard drive) will remain.
Reconfigure File History as required.