how to change the column heading back to ABCDE instead of numbers

[chester]

Could u assit me in changing the column headings back to its standard settings.
instead of the column heading being ABCDEFG and so fort it says 1234567.
How do you change it back

 

[Dennis]

Tools - Options - General Tab - Uncheck R1C1 reference style

 

[chester]

Thank you Dennis

Tools - Options - General Tab - Uncheck R1C1 reference style