The Show Previous and Show Next buttons don't work
To access the Header and Footer toolbar, click Header and Footer on the View menu.
Use the Show Previous and Show Next buttons to move to the previous or next header or footer that is different from the current header or footer. If headers and footers are the same throughout the document, the insertion point won't move from the current header or footer. If a document contains different headers or footers in its sections (section: A portion of a document in which you set certain page formatting options. You create a new section when you want to change such properties as line numbering, number of columns, or headers and footers.), however, the insertion point will move from the header and footer in one section to another. You can also use the buttons to move from an odd header or footer to an even header or footer, or to move from a unique first page header or footer to the next header or footer.
The Link to Previous button doesn't work
You use the Link to Previous button to create different headers and footers for different sections in your document. This button is not available unless a document is divided into sections, and it is not available in the first section in a document.
When you split a document into sections, the headers and footers are identical for each section until you specify otherwise. You have to break the connections, or links, between the headers or footers in each section if you want to use different headers and footers. When you see the text Same as previous above the header or footer area, that section has the same header information or the same footer information as the previous section.
Note Although you use this button to make the headers and footers for a section the same as those in the previous section, you also use it to make the headers and footers for a section different from those in the previous section. The button acts as an on and off switch, but the button name doesn't change.