In the Office apps, you can undo and redo an action or a series of actions.
Select Undo or press Ctrl + Z.
To remove more than one action, select Undo until the file returns to what you previously had.
Note: You cannot undo an action like saving a file, but you might be able to AutoRecover it.
Select Redo or press Ctrl + Y.
To redo more than one action, select Redo several times.