Working on Excel 2003

Machine One:  When dragging fields to the data section of a pivot table, the
default function is "sum."

Machine Two:  When dragging fields to the data section of a pivot table, the
default function is "count."

Question:  Is there a way to set the default function of the field setting
prior to creating the pivot table?

Another question:  Is there a way to globally change the field setting after
dragging all to the data section?  I am comparing monthly data, so I have 12
fields that I drag to the data section (Jan, Feb, Mar, etc)  As of now, I am
changing them one at a time from "count" to "sum" but there has to be an
easier solution.

Any help???