When you create a header or footer in a Microsoft Word document, and then create a section break, the first section's header/footer settings will be duplicated in the subsequent sections.
(click image to enlarge)As you can see in the picture above, there is a button called "Same as Previous" in the Header and Footer toolbar (the button with two pages side-by-side, with a little arrow connecting the two). It is automatically engaged when you create a new section. When it is engaged, the words "Same as Previous" appear directly above the footer's borders, on the right.
In order to work on the headers/footers in one section independently of the headers/footers in the previous section, you need to remove this link between them. To do so, in the second (or following) section - the section in which you want a different header/footer - you need to click that "Same as Previous" button to disengage it. When you do, the words "Same as Previous" disappear [see below]; you can now work on the subsequent headers/footers with no impact to the previous headers/footers.
(click image to enlarge)Just remember: Each time you create a new section break, you will have to disengage that "Same as Previous" button, if you want that new section's headers/footers to function independently.
Hope that helps!
To find the "Same as Previous" button:
On your Header and Footer toolbar, at the far, upper right, is a small down-arrow that allows you to change your toolbar options.
(click image to enlarge)If you click that aroow, it will expand to display the words, "Add or Remove Buttons."
(click image to enlarge)As you hover over that text, it will expand further to the right, displaying "Header and Footer," and then - finally - a complete list of buttons available to this toolbar, including today's favorite, "Link to Previous."
(click image to enlarge)There you go! Easy-peasy. :)
