Hello Spider,
To copy a soundfont preset from one soundfont to another, you do this:
Your first misconception is that there are two windows. This was correct in Polyphone 1.9. Open both soundfonts by dragging the icon into the Polyphone window. Both soundfonts will appear as a tab, along with the home tab. As of version 2.0, there should never be more than one Polyphone window.
Select the source soundfont's tab and open the preset dropdown menu. Click on the preset you want to copy (it should look like 'xxx
xx [name of preset]'), and press Control-C (or the shortcut to copy on other platforms) to copy it.
Now select the destination soundfont's tab and click the button saying 'Presets' (you do not need to open the dropdown menu). Press Control-V (or the shortcut to paste on other platforms) to place the preset in the destination soundfont.
Note: Make sure the number of the preset in the source soundfont (the 'xxx
xx' on the name of the preset) is not the same as any other presets on the destination soundfont.
If you find this confusing, you can always download
Polyphone 1.9.
P.S. : Make sure you have permission to copy the presets. I do not condone or encourage copyright infringement.