Excel Cell References are different to normal

[Guest]

recently my spreadsheet has changed the format of my cells, instead of
letters on the columns, it now gives me numbers, also when i do an addition
of a lot of numbers in the equation does not state =sum(d1:d78), instead it
gives somthing like this =SUM(R[-24]C:R[-2]C) , can anyone help or explain

 

[Guest]

From the menu bar, Tools > Options, select the General Tab, clear the
checkbox for 'R1C1 Reference Style' and click OK. (If it's already cleared,
set it and click OK, then go back and clear it).