This is not a global option.
Must be done on each workbook.
One way around this is to open a new workbook then save as a Template with the
options you want.
Name the workbook BOOK and save as MS Excel Template(*.xlt)
Do not enter the extension, Excel will do that for you.
Store in your XLSTART folder and it will become the template for all workbooks
when opened via File>New
Note: this will not affect previously saved workbooks.
Gord Dibben Excel MVP