N.B. You’ll need to have a program installed to view Microsoft PowerPoint presentations. If you don’t have PowerPoint, you have some free alternatives. 1) PowerPoint Viewer is free from Microsoft. It allows you to view (but not edit or print) presentations. 2) Open Office is an Open Source (free) Office suite that competes with Microsoft. 3) I’ve heard that Google’s online applications (Google Apps) now handles presentation files.