Hey Keith,
Sorry for the delay. If you are unable to insert a PowerPoint file, let's check a few things.
First, please make sure that PowerPoint 2010 is the only version of PowerPoint (or PowerPoint Viewer) installed.
Next, try running a Repair on PowerPoint 2010. If there is any option to add optional features please select ALL of them.
Let me know how that goes and we can take it from there.
Thanks,
-Ryan