Microsoft has released new formats .docx, .xlsx, .pptx in Microsoft Office 2007 / 2010 Suite adding extra capability. Office Suite is pretty expensive and sometimes you might not have access to it.
In case if you have received a .pptx ( 2007 and 2010 ) or .ppt ( 2003 or earlier ) versions of PowerPoint presentation files, you can view them with all embedded effects using a free tool provided by Microsoft. You’ll just need to download and install on your local windows system to use this software. This is designed to work on Windows 7/ Vista/ XP / 2003