Right click the folder, choose settings/properties, go to tab "Security" and check if your username got write & read access to this folder and all subfolders. If not, grant it to your user by adding your username via the "Edit/Change" button, and put your username (and domain if needed ) in the lower edit field.
See this video maybe it helps:
http://www.makeuseof.com/tag/fix-acc...rs-windows-10/
Or just search for ""Windows 10 folder access" or "Windows 10 folder permission"