Adobe Reader

The free Adobe Reader lets you view and print Adobe Portable Document Format (PDF) files across different hardware and operating systems.

(http://www.adobe.com/products/acrobat/readstep2.html)

PowerPoint™ Viewer

The PowerPoint Viewer lets the user view full-featured presentations created in PowerPoint 97 and later versions. The PowerPoint Viewer also supports opening password-protected Microsoft PowerPoint presentations.

(http://office.microsoft.com/en-us/downloads/CD010798701033.aspx)