Supernatural EP downloaded before Pets?

[AlwaysHunted]

So in the beginning I started off with -
Sims 3
Late Night EP
High End Stuff EP
Supernatural
I downloaded them in that order, however today I bought and installed Pets EP and I can't get the launcher to open/either to work. I heard that I need to uninstall them both and then reinstall them both with Pets being first. I'd hate to do this though because then the others might get messed up not to mention I lose all of my progress. Don't get me started on how my computer hates Create A Sim. Thanks ahead for your time.

[rumbutter]

the game always plays from the newest installed realesed game you installed  which for you is supernatural pets is older then supernatural (pets will combine for playing )  another example of this is say you go buy generations the game will play from the supernatural's  as it is the newest installed released you installed