We support the Microsoft PowerPoint Viewer but it does have some limitations as it requires full screen and licensing from Microsoft and so we highly recommend, that you simply spend $40 and get a PPT > SWF convertor (Power Point to Flash converter). Microsoft Powerpoint 2010 also the option to convert PPT files to SWF. Nevertheless We recommend these two:

http://www.acoolsoft.com/powerpoint-to-flash-overview.html
http://www.flashdemo.net/ppt2flash.html