Video and Share Screen HELP!

Hello, this is my first post.

So, I switched over to MAC a MacBook Air, and love it.

I have one question though…

I need to be able to use my MacBook in company presentations. I bought a projector and the "display port to HDMI" connector.

So, now I can connect the projector to my Mac and it works great…for PowerPoint, and only PowerPoint.
As soon as I put anything on my screen that is NOT PowerPoint the projector just shows a blank shot of my desktop screen (no icons).

I need to be able to show other files on my computer, not JUST what I have in PowerPoint.

I have the same problem with Skype. When I chose "share screen" in Skype, the people on the other end of the "line" can only see only PowerPoint slides that I am showing, anything else and their view goes blank…

This must be some security thing in my MacBook that prevents the "showing" of anything except PowerPoint, but I need to change this.

Help!

Thanks in advance,
John

Haven't used PowerPoint that way in a while. There might be a setting within Powerpoint that is causing this but here are a couple of things I would try in the way of troubleshooting:

Open System Preferences and go to the Displays preference pane. From the Arrangement tab click the Mirror Displays option just to see if the same image appears on both screens. If so everything is connected correctly.

You might find some of these tips helpful ATPM 14.12 - How To: Taming the Two-headed Monster: Using Two Monitors With Your Mac.