Click the Review tab.
Then click the Track Changes button,
and then click Highlight Changes.
Select the Track changes while editing check box.
Select the When, Who, and/or Where check box.
Click an associated list arrow, and then select the option.
Select or clear the Highlight changes on screen or List changes on a new sheet check boxes.
Click OK, and then click OK again, if necessary.
Make changes in worksheet cells.
The cell containing the changes has a blue outline.
To view tracked changes, position the mouse pointer over a cell.