Dave
There is no global Office setting that would control the Headers/Footers for
workbooks/worksheets.
Possibly your workbooks were based upon a Template that had the code, but if
most other workbooks don't have it, the Template is no longer being used as
the basis for new workbooks.
Delete the code from the module for this file and save.
To find the "lingering" ones would require manually checking each workbook or
using Chip Pearson's "remove all VBA code" which may be overkill and dangerous
if you have other code you need to keep.
For reference see....
http://www.cpearson.com/excel/vbe.htm
Gord