While you have Excel open, it is constantly checking in the background for potential errors in your worksheets. If an error is located (or, at the least, what Excel thinks is an error), then the cell is “flagged” with a small green triangle in the upper-left corner of the cell.
If you don’t want Excel to check for errors, you can turn the feature off by following these steps:
- Display the Excel Options dialog box. (In Excel 2007 click the Office button and then click Excel Options. In Excel 2010 and Excel 2013 display the File tab of the ribbon and then click Options.)
- Click Formulas at the left side of the dialog box. (See Figure 1.)
- Clear the Enable Background Error Checking check box.
- Click OK.
Figure 1. The Formulas area of the Excel Options dialog box.
Any existing green triangles should disappear, and Excel stops checking for errors.