How do you fix The Sims 3 without the booklet code?

Ok, so The Sims 3 for PC stops working on random occasions almost every time I try to play it. I uninstall it and reinstall it every time, and it seems to work out, but now it's not working. It keeps saying there's an 'error' and whatnot, and still won't work if I uninstall and reinstall it back in. What's worse is that I can't find the booklet with the code so I can attempt to reinstall it back in. I need help! Is there a way to fix it without the code? Please tell me if you know! I love The Sims and haven't played it in a little over a year now!!