Whenever you collaborate with a number of your colleagues in producing or editing a document, you should consider tracking the changes each user makes. When you turn on Track Changes, Excel 2007 highlights any changes made to the workbook in a color assigned to the user who made the changes. When you have a question about a change, you can quickly identify who made it and verify that it is correct.
Turn on Track Changes
Click the Review tab.
Click Track Changes.
Click Highlight Changes.
Select the Track Changes While Editing check box.
Select the Who check box.
Click the Who down arrow.
Click Everyone.
Click OK.
Tip
If your workbook’s changed cells aren’t marked, you can have Excel display them by clicking the Review tab, clicking Track Changes, clicking Highlight Changes, selecting the Highlight Changes on Screen check box, and clicking OK.