Why do the column headers show numbers instead of letters? How do I change my column headings so they are back to letters instead of numbers? Excel 2007

I got a call from user asking me why the column in Excel 2007 displayed numbers instead of letters and how to change back?

 A quick googling led me to this:

 

Why do the column headers show numbers instead of letters? How do I change my column headings so they are back to letters instead of numbers?

Change column headings to letters in Excel 2007

1. Click the Office button, and click Excel Options.
2. Click the Formulas category
3. Remove the check mark from 'R1C1 reference style'
   

Change column headings to letters in Excel 2003 and earlier versions

1. Choose Tools > Options and select the General tab.
2. Remove the check mark from 'R1C1 reference style'
   

- wong chee tat :)