Make sure that your computer meets the minimum system requirements printed on the box.
Close any other applications and disable virus protection before starting The Sims.

In addition, you may need to end any background tasks in order for the game to run its fastest. To do this, hold <Ctrl> and <Alt> and then tap the <Delete> key. This should bring up the "Close Programs" window.

Highlight an unnecessary application and press "End Task". Repeat this procedure to close any other programs excluding "Explorer" and "Systray", then try installing again.

Make sure that you are using the most current available drivers for your sound card and video card and that you have DirectX 7 installed.

If you have any questions concerning how to update your video drivers or installing DirectX, please contact your hardware manufacturer.

If the game is still choppy, turning down the detail levels in Options Mode should help. Try turning off some of the effects, particularly Shadows and Lighting. Press the <t> key in the game to activate the frame counter, which shows how many Frames per Second (FPS) your computer is delivering. This should increase as you make these changes.