HELP! Need help setting up global margins in word 2007

I just upgraded from word 2003 to 2007 and am having trouble with my margins
(being too big) when I open old .doc files. I must be able to open .doc
files w/ margins at about .5 all the way around because I am exporting a
massive amount of files to .doc from my accounting software and need to be
able to open and print w/ the correct settings instead of having to change
the margins each time. I had this issue before but i went in and changed the
margins to .5" in the normal.dot template and then when i open the file it
would change the margins automatically.

I just installed word 2007 and made all kinds of templates w/ the correct
margins necessary in hopes that it would change the files when I opened them.
It didn't work. What's weird is that when I create a NEW document it puts
the correct margins .5 all the way around, but if i open a .doc file it puts
1" margins all the way around.

If anybody could help I will be forever in debt to you.