A family of Microsoft word processing software products for creating web, email, and print documents.
Insert a Next Page Section Break at the end of the third page and in the second Section of the document (after that Section Break), click on the Link to Previous in the Navigation section of the Header & Footer Tools>Design tab of the ribbon to unlink the headers and footers in that section from those (even if there are none) on the first three pages and then use the Page number facility in the Header & Footer section of that tab of the ribbon to access the Format Page Numbers dialog and set the page numbering to start at 1.
If you are writing a book, see Daiya Mitchell’s “So you want to Write a Book with MS Word” (but good information even it not writing book) at:
http://daiya.mvps.org/bookword.htm
For more information on the use of Headers and Footers, see