Well, I'm happy for the gurus to argue over the details.

The facts are that the specific actions I took (un-install, clean the registry, re-install) solved the problem. And it is the cleaning the registry which is the key factor here. The un-install and re-install had been done several times before with absolutely no effect - the reg clean was the only difference. And I have not changed the compatibility of the either program at all.

Whether the installation routines access any of these registry keys or not, it is hard to argue that they did not have an effect on batch being able to call converter.

I'm just happy to have fixed it.