If you do not have PowerPoint, you would still be able to view and print these PowerPoint presentations if you download the PowerPoint 2007 Viewer, which is available free at the Microsoft Web site. You can also edit these presentations using free programs. Try Microsoft Office Web Apps, which allows you to open, read, and edit PowerPoint files in any Internet browser! Finally, OpenOffice.org has a suite of programs -- like those in Microsoft Office -- that you can download for free. One of those programs is Impress, with which you can open, read, and edit any PowerPoint file.