I learned this tip today at one of the threads on the officials. Some of you may have heard of this free program before, but it's new to me. It's called GameBooster and it essentially shuts down all programs in the background so you can run a game faster. When you exit out of your game, it returns your system to the way it was. I was worried this would harm my computer or it would shut down programs I don't want, but that hasn't happened. When you click the configure program during setup it shows you the files and you can choose to not have them shut down if you want. I just went with the ones it selected.
I've been trying this program and I'm impressed so far. My game is running smoother and I especially noticed it was faster in CAS. I have a mega TON of cc and it usually takes forever to load stuff in CAS. I have one of those all-in-one computers with an integrated chip that shouldn't even be able to run the sims (someone said), so this is great for me. Here's the link if you want to try it. (Btw, there's a link next to the Download button to a program that says it scans your PC for Windows errors, but I noticed it also installs some toolbars, so I didn't install it. I only installed GameBooster.)
http://www.iobit.com/gamebooster.php