Can you tell me the easiest way to add page number to PDF file generated from MS Word

This video shows how to use A-PDF Word to PDF to add page number to the created PDF file while converting Word to PDF. See more at: http://a-pdf.com/faq/what-is-the-easiest-way-to-add-page-number-to-the-new-pdf-file-while-converting-word-to-pdf.htm