How can I speed up my computer?

My computer runs okay, and plays certain games fine, but when it comes to some games, the frame rate is slow, the gameplay is jerky and I can't really do much. 3D games are the ones with the most problems. I have my computer settings set to High Performance, my nVidia is set to performance and i turned all the graphics settings down but the games are still jerky. I have a Compaq Presario F700 laptop, and I tried Game Booster by IOBit. Thanks :)