MediaShout needs Microsoft PowerPoint software installed on your computer to play Slideshow cues. There is only one version of the PowerPoint Viewer that has the functions needed to enable this, and that is Viewer '97. Other than this, the only other options are FULL versions of PowerPoint 2003, 2007, or 2010 (in version 4 only, and with build 199 and higher). None of the free viewers after PP Viewer '97 will work.
Microsoft no longer supports PowerPoint Viewer '97, so it is no longer available from their website. Please download the installer file attached to this article if you need this software, then unzip the file and install.
Note: If you have a full version of PowerPoint installed on your computer already, this viewer is not needed, and may even be detrimental to MediaShout performance. Please do not install it if that is the case.