Sims pc game wont let me play! :(?

i installed the sims, sims livin large, sims house party, and sims vacation, all in that order. when i click to play it says i have installed another expansion pack after vacation and it needs to reinstall vacation to work. i click the reinstall on and then it asks me if i then want to uninstall vacation. which i dont want to do! if i uninstall vacation it uninstalls all of the other sims i installed too! and if i install them all over again it just does the same thing! help me......