Anyone can make mistakes, especially when creating a complex worksheet. Excel provides a way of backtracking over, or undoing incorrect or unintended actions.

To undo an action, click the Undo button on the standard toolbar.

This will undo the very last action you performed. If you continue to click the Undo button, the next most recent action will be undone, and so on, for up to 16 actions. You can also click the downward pointing triangle, to show a list of recent actions. You can select actions from this list and then click the list to undo them all at once.

If you want to redo an action (perform an action that you undid with Undo), you can click the Redo button on the standard toolbar.

You can also use a dropdown list to select multiple actions to Redo, in just the same way as with Undo.

The Undo and Redo features are also available on the Edit menu from the menu bar when there are actions available to be undone or redone.

You can also repeat an action using the Repeat feature on the Edit Menu. If you perform an action on a cell, making it currency style for example, you can then click on another cell, or select a range of cells and use Edit -> Repeat, to repeat the action on the additional cells.