So I decided I wanted my old stuff back. My phone has a better answering machine facility. I do not want this annoying: "The magic jack customer blah blah is unavailable" message to keep playing.
Any way, here is how to do it:
HKEY_CURRENT_USER\Software\talk4free\USB Softphone\Options\Calling Options\CFNoAnswerTarget. This is a string with null value initially. Just change that null value to your own magic jack phone number. Use a format of xxxyyyzzzz. No hyphens no country code. Nothing. You should also see that your vmail icon on the MagicJack display board is now dimmed out (but do not press it).
Make sure your phone answering machine facility is enabled. Otherwise, you won't like this.