To save a PowerPoint presentation with notes pages to a PDF on Windows, create notes pages by selecting "Notes Page" in the "View" tab, then print the presentation to PDF by selecting "Notes Page" in the print layout. On a Mac, view notes pages by selecting "Notes Page" in the "View" menu, then print to PDF by going to "File," "Print," selecting "Notes" under "Print What," and choosing "Save as PDF." Both methods allow saving the presentation with notes to a PDF file.