By default you can only restore deleted files on OneDrive for Business by following the directions located on the Microsoft Office Empty the recycle bin or restore your files web page. If you would like to restore files that have been changed, but not deleted then you must turn on versioning. Versioning is not turned on by default and Information Technology strongly recommends that users enable it. With versioning turned on users can view and restore old versions of files after they have been modified. For directions to turn on versioning please visit http://it.wvu.edu/services/office365/onedrivebusiness/enabling-and-using-versioning.