Paper resizing

[KKW]

I have set the printer preference to A4 under the
Printing and Other Hardware menu (Windows XP). When I go
to the page setup menu in Excel/Word/Notepad etc, the
paper size is however set to Letter as default. How do I
change it to A4? It swithces back to Letter everytime I
open up a new document.
I've got Australian 'regional settings', and the "allow
A4/letter paper resizing" under the
tools/options/international menu is not ticked.