After working on my sister's computer for some time today, she was finally able to install the base game, the superpatch and the other games she wanted without a problem. What my brother in law did was, he ran the CC Cleaner and went into the registry files and found files that had sims3 and launcher in the subject line that needed to be fixed and clicked fix these files. She had all games uninstalled and there were still files left in different folders and the CC Cleaner cleaned those and the program System Mechanics found a bunch of folders marked the sims3 that were left behind and those got deleted, so after much hair pulling and crying and whining, she is now able to install everything without the error message, lol. Just remember, install base game, superpatch and then the games you want.
