I am trying to change the settings for saving documents.
I am in "Settings/System/Storage/Change where new content is saved".
Currently Documents are set to "This PC (C:)". Using the drop down menu, I change the entry to "Data (F)" which is the drive where my Documents folder resides. I then click Apply and get a message saying "We couldn't set your default location. The operation did not complete successfully. Try again in a bit. The error code is 0x80070005, in case you need it."
Trying later makes no difference and the only references I can find to that error number refer to Windows Update and the Windows Store.