Restoring Previous Version of a File

Microsoft Office offers Version History for Word, Excel and PowerPoint files. This feature may help you recover a usable copy of a file when it becomes corrupt or it cannot be opened by the source application. To access version history of a file:  

1. To do this go to portal.office.com. 
2. Click on OneDrive icon
3. Go to the folder that contains the file
4. Click on the 3 dots to the right of the file name
5. Select Version history
6. In navigational pane on the right choose which dated version you wish to look at or edit..