Microsoft offers the Office product in several forms, and one of those will not work with MediaShout.  The delivery methods are:

• Disk, the traditional method,
• Download (or preinstalled), a no-media version of the disk based installer, and
• Click-to-Run, a version that downloads components as you need them via the internet.

Because the Click-to-Run version doesn’t install all of the components, that version doesn’t support interaction with other software products like MediaShout.

To determine if you are using the Click-to-Run version, check under "About Microsoft PowerPoint" and look at the version info.  It should say "(32-bit)" or "(64-bit)" next to the version number.  If it says "Click-to-Run" you will need to switch to a full installation of Office onto your computer.  Microsoft has an article that describes this process:

Click-to-Run: Switch to using an MSI-based Office edition
 

Once you have installed from an MSI-based installer, the PowerPoint application will be installed on your computer in a way that will be accessible by MediaShout.