what extension is used for powerpoint?
 .potx file for PowerPoint 2007 and newer, .potm file for a 2007 or newer macro-enabled presentation, .pot file for PowerPoint 97 through 2003, .ppsx for PowerPoint show 2007 or 2010 versions, .pps for PowerPoint show 2003 and earlier versions, .pptx for PowerPoint presentation versions 2007 and 2010, .ppt for PowerPoint presentation versions 2003 and earlier. 