Re: Windowed mode upon startup

@qiqibot  If you play through Origin, you may have a box for command line arguments, into which you could put -w to force windowed mode.  I'm not in front of an Origin/Windows install right now to check, but it you'd access it by right-clicking on the Sims 3 icon in your Origin game library, selecting Game Properties, and then maybe Advanced Launch Options.

In macOS, you can hit cmd-enter immediately to switch to windowed mode.

Otherwise, you'd need an options.ini file, which means you'd need to launch the game once to create it.  But of course you could just disable fullscreen from the Main Menu.  If you do happen to already have an options file though (in Documents\Electronic Arts\The Sims 3), search it for "fullscreen" and set it to zero.