MS Excel: Display comment indicator next to cells with comments in Excel 2007
Question: When a comment has been inserted in a cell, the little red triangle is not being displayed to indicate a comment in a cell. What can I do to remedy this in Excel 2007?
Answer: As you can see, the little red triangle is not being displayed in cell A1 even though there is a comment in that cell.
Click on the Microsoft Office button 
in the top left of the Excel window and then click on the Excel Options button.
When the Excel Options window appears, click on the Advanced option on the left. Then scroll down to the Display section in the right side of the window and select the option called "Indicators only, and comments on hover".
Now when you return to the Excel spreadsheet, you should see the comment indicator. The comment indicator is the red triangle positioned in the top right corner of the cells that contain comments.
