tenforums[.]com/tutorials/92892-sync-any-folder-onedrive-windows-10-a.html
Microsoft has always hired the best tech folks they could persuade to join the company, but common sense has Never been a requirement, or a strong point. That's Very apparent if you want to add an existing folder to sync with OneDrive today. With the current OneDrive app in Win10, you can't. Nor can you do it opening OneDrive on the web. Instead you can manually copy whatever to a OneDrive folder Every time you want to update files or add something new, or you have to use the Command Line to create a link between an existing folder and the OneDrive folder in Win10 that does sync. This article shows how to do that.