pdf file: You need Adobe Acrobat Reader (version 7 or higher) to view this file. Download the free Adobe Acrobat Reader for PC or Macintosh.
docx file: You need the Microsoft Word program, a free Microsoft Word viewer, or a program that can import Word files in order to view this file. To learn more about the free Microsoft Word Viewer, visit the the Microsoft Office Compatibility Pack.
The MP4 file type is primarily associated with 'MPEG-4'. Play MP4 files with various players such as QuickTime or RealPlayer.