Instructions
Locate the shortcut for "The "Sims" game launcher. If it is not on your desktop or in your game folder, use the Start menu search bar to find the shortcut.
Click on the shortcut with your right mouse button to make a pull-down menu appear.
Select "Properties" at the bottom of the menu.
Click on the "Shortcut" tab to display that list of options.
Click on the text inside the "Target" box to make your cursor appear. Hit the "End" button your keyboard to move to the end of the text string.
Type " -w" with no quotations at the end of the text that is already in place. The exact keystrokes you will hit are "Space," "Dash" and "w."
Click "OK" at the bottom of the box. When you open your "Sims 2" game with this shortcut, it will run in windowed mode.