How do I get Sims 3 launcher to work?

I have been working on this problem lately. My best friend who knew a lot more about computer than I do tried his best to fix the Sims 3 Launcher. Recently, when I tried to play Sims 3, the Launcher would not work. Every time I tried, I get the error message. My best friend and I tried everything to get the Launcher going but to no avail. What are we doing wrong? I love Sims 3 and I mean I LOVE SIMS 3. But every time I tried to get the game going, it crashed. My O/S is Windows XP and that's pretty much I know about my computer. Please help?