Try a clean reinstall following the instructions here:
http://simswiki.info/wiki.php?title=Game_Help:TS3_Uninstall and here:
http://answers.ea.com/t5/The-Sims-3/Help-Guide-All-in-one-fix-except-hardware-issues-PC-only/m-p/734448#M36281 where it says Delete game installers
Manually delete everything if above method does not work:
https://help.ea.com/article/manually-uninstalling-the-sims-3
Make sure everything Sims is gone from your computer before reinstalling
If the game still shows in your Uninstaller Menu afterwards, you can use CCleaner to get rid of those.