PowerPoint reader (.ppt) I searched for a PowerPoint player (ppt from Microsoft Office) but I couldn't find what i needed.
Is there a module that can display PowerPoint files on Drupal sites?
You can use the Embedded Google Docs Viewer module:


  The Embedded Google Docs Viewer module adds a new formatter to the File field using the Field API. This formatter displays PDFs, Microsft Word documents, Powerpoint presentations, or Excel spreadsheets directly within a Drupal node.


There's a tutorial that details how to use it on the module page.