All you do is click "Export" and save as a .png file.

If they still get a background it's because there graphic program isn't supporting the transparent alpha channel for some reason.  Some of the earlier beta versions of Paint Shop Pro IE: 7.0 and 8.0 had problems, but patching up to 7.04 and 8.1 fixed it.

If they are using PSP and need the patches, I can dig out the links and post them.

But so far as I know there is nothing to set in Poser to get it to save .png files with a transparent alpha channel.  I believe it's an automatic process.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi