To get the game running in a full-screen window, you'll want to start up the app, load up SimCity and set the game to run in windowed mode.

How to turn on Windowed Mode in The Sims 2: Legacy Collection While it’s not listed in the in-game options menu, The Sims 2: Legacy Collection does have a Windowed Mode, and activating it is as ...

The change primarily impacts old DX10 and DX11 games running in Windowed and Borderless-Windowed mode. Modern games using DX12 already benefit from this. That said, Microsoft has cautioned that: ...