Sims 3 World Adventure Installation Problem

Ok with the installation guide on this one I was a bit confused and couldn't find The Sims 3 in the first step in the registry and so went on to other steps. Now I can't install World Adventures as it says something about regional codes :/ And It wont even boot up to ask me how to install.

I do have Late Night, Generations, and Ambitions all installed, not sure if that affects what I install or try to.

Try this:

Go to registry again.
click on File>Find>type in "sims" and search till you find it.

Its most likely hidden somewhere, same thing happened to me.