How can I add a powerpoint presentation to a slide and play it in the slide? Any help would be appreciated. I have used Embedded Google docs Viewer module but when I view it in the slide it says "No Preview Available". please let me know of a solution if any.
You can either convert it to PDF or to SCORM (this requires a tool, for example this one: http://www.ispringsolutions.com/ispring-pro?ref=home)
Then PDF and SCORM packages can be added inside slides
This is not possible out of the box.
You should either develop an additional module, or rely on an existing library (for example http://groupdocs.com/blog/pdf-document-viewer-module-for-drupal)