trying to export a PNG and keep my Transparent background

HI All,

I am able to see a transparent background using the render preview as picture below. But when using a render out or F12 I lose the transparency. Can I get some direction here please?

This is Cycles V 2.68 win7 platform

NOTE the checks showing Transparent. (white scribble)

F12 out to check it. Transparency turns black.

If it is the World what do I switch to have my world stay transparent?

Looks like you are using some compositing nodes. Check that the output there has alpha enabled.

Thanks Organic I will look into that. This is someone else Blend file I am using for a movie I am putting together and it is always interesting sleuthing around Another’s way of doing art or modeling.

Where do I enable Alpha in composite Nodes? Is it on the Node itself or is it the way it is strung together?
Here is a grab from the Composite Nodes view.

P.S thanks for not being sensitive, appreciate it. (Since you cannot see smiles nor hear inflections)

Thanks Organic I recieved a pic from the artist explaining how to. For those how Duck Duck or Googled this here you go.:

Those of you who only need the Earth and Moon Still with a Transparent Background: