SimsVIP has a post on the official Sims 3 Forums that helps users who are having problems with The Sims 3 since installing the Pets Demo. There’s also informative info on what to do before you install the Demo. There’s also a note from Twallan about what to do if you have his Mods installed.

| Help Forum I | Help Forum II | Twallan |

Source: SimsVIP