I noticed working one day that Excel was no longer letting me make edits directly in cells (when I double-click on a cell). I needed to go to the formula bar to make my edits, which is much more time consuming and mouse intensive. After living with this for a week or so, I discovered the issue and how to correct. Note that I'm using Excel 2007, so your version may be different. Click the Office Button (upper-left round Office button). On the bottom of the menu, click Excel Options . - This will open the Excel Options dialog box. Select Advanced from the left-menu. Check the box, Allow editing directly in cells . Click the OK button at the bottom of the dialog box. I'm not sure how this setting got changed, but nevertheless it solved the issue of not being able to edit directly in cells.