LiaKnow You're not taking any more of my time than I want to spend, really. I do this because I enjoy it.
My next suggestion would be to create a new admin Windows account and try playing there. Make it local, as in, don't link it to your Microsoft account or any email address. You'll be able to launch the game without reinstalling anything, but your saves and other content won't be available, and you'll need to edit Options.ini again (if the game doesn't work the first time) to reimpose windowed mode.
Double-check that the Nvidia GPU is still selected in the Control Panel in the new account, and for now, make it global, at least while you're trying to play Sims 3. Restart your computer after imposing the setting if it's not already selected.
If that doesn't help, try playing in a clean boot, still in the new account:
https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd
The one service to leave enabled is the EABackgroundService, which the EA App needs in order to run. Disable the rest as described.
When you reboot your computer, go through the Task Manager's background processes list shutting down any service that doesn't absolutely need to be running, for example anything from MSI Afterburner to RGB software might still be enabled. If you accidentally kill a critical process and it doesn't restart on its own, just reboot your computer again.
Don't open anything other than Sims 4 and the EA App while testing, not even a browser window.
If this helps, you can selectively reenable services until you find the culprit, then either leave that disabled or (if it belongs to an app you want to keep using) let me know what it is so we can try to fix the underlying issue.
If it doesn't help, please post the Reliability Monitor error associated with the crash in the clean boot.
If you decide to reinstall Windows, that's fine, and understandable; this is your time, after all. (It doesn't take me that long to write a post.) At this point, it might be faster to reinstall Windows and your various apps than to find the cause of the issue. But it really is up to you, and I'll keep trying, and go get a second opinion if and when I'm out of ideas, as long as you're still interested.
