Change the "Number format" in the Page Number Format dialog box.
To display the dialog box: First activate the header/footer view, for
example by double-clicking the header (in Word 97-2003, you can click View |
Header and Footer). Then, in Word 97-2003, click Format Page Numbers on the
Header and Footer toolbar. In Word 2007, click Page Number | Format Page
Numbers on the Header & Footer Tools Design tab.