Social Theme: "Sign-up" goes to - Can't Find place to change URL

I can't find where to change the URL in my Theme Settings for redirecting the "Sign-Up" link from to...

When looking at another forum thread, it said to...
"..go to Theme Options and then Blog Message Settings and change the URL there.."

I did this, but I couldn't find "Blog Message Settings" anywhere.

Another thread said to make sure the "Anyone can register" is enabled in the Settings --> General page and it is.

What should I do?