My Sims 4 starting up in a tiny window

Nazj8  Try forcing the game to open in windowed mode.  (I realize it looks like it's there already, but it may not be.)  Go into Documents > Electronic Arts > The Sims 4, open Options.ini, search for fullscreen , and set it to 0 (zero).

If that doesn't help, please provide a dxdiag.  Hit Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop.  From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.

Hi, I seem to be having the same issue with my game window and I tried forcibly setting the game to windowed mode like you instructed above but it was already set to 0 and didn't fix the issue. So I tried the inverse and set it to 1 instead and it kinda worked. The game could run but it would keep flashing white every few seconds. I tried to play on one of my saves and it refused to load, keeping me at a dark screen (however I could exit the game just fine). Then I rebooted the game and tried to change the game from fullscreen to windowed mode which didn't put it into windowed mode and refused to respond. I couldn't even close the game or force quit it via task manager, so I had to restart my computer again. Please help.

Electricnite​  Thanks for the dxdiag.  It looks like you're using a mod manager that's crashing occasionally, which means you're probably using mods.  So please remove the entire Mods folder and test again, AND make sure that your mods manager doesn't reinstall the mods.

If that doesn't help, open the Task Manager and end any Killer Network-related services, which would likely be in the background services list.  Killer software is crashing too.

Ok so, I removed the mods folder and closed my mod manager so it didn't reinstall my mods, but that didn't work. Then I ended any Killer Network related processes like you said and that also didn't work. I attached another dxdiag for after the fact, just in case.

Electricnite​  Try playing with your computer offline.  You can sign into the EA App and put it in offline mode, then disable wifi and/or disconnect the ethernet cable before pressing Play.

If that doesn't help, please try playing in a clean boot:

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 the game freezes or crashes in a clean boot, please try again, except with your computer offline again.

I did the clean boot and it didn't work. I even tried another clean boot and booted the game offline, but that still didn't work. I left 5 background processes active through my task manager when directed to it: EALauncher, EarTrumpet, Everything.exe, RtkAudUService64.exe, and SecurityHealthSystray.exe. For the Services tab in System Configuration, I turned off everything but EABackgroundService and hid all Microsoft services. 

Electricnite​  I don't know what EarTrumpet is, but it's not a necessary app unless it's for accessibility.  Even then, it would be best ot disable it temporarily to see whether it helps.  Everything doesn't need to be running either, and it's definitely not necessary since it's simply a search tool.  RtkAudioService is a component of the sound driver, so leave that alone.

Other than the above, please 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 asked to answer some security questions instead.)  Don't import any settings from your main account either.  You'll be able to launch the game without reinstalling anything, but your saves and other user data won't be available.

The point here is to see whether the problem is some setting in your main account.  If the new account works, we can try to find the relevant setting.  If it doesn't work, the problem is more global, and we can also discount any problems that wouldn't carry over from your old account.

So I tried rebooting it again, this time without EarTrumpet and Everything.exe but that didn't work. I made a new Windows profile, like you said to do, and made sure everything that was disabled before was disabled again. That also didn't work. I ended up searching through the forums again to see if there was anything close to this issue and I found one post that said switching the GPU preference from Nvidia to Intel in graphics settings worked for them. I tried it and that completely solved the issue. Now I'm just going through the Nvidia app to see what settings is causing this issue in the first place.

Electricnite​  You could do a clean uninstall and reinstall of the Nvidia driver.  That should remove the App as well and reset all your options.  It would also address any issues with the driver, not the sofware overall but problems like a corrupt install.

https://crinrict.com/blog/2019/02/clean-re-install-of-graphics-drivers-with-display-driver-uninstaller-ddu.html