Sims 4 (Steam) and EA will not launch Sims 4

@Simtinee  If you've enabled Steam's family sharing, please disable it.  EA games don't get along with this feature.

Otherwise, please create a new admin Windows account on your computer and try playing in that account.  Make it local, as in, don't link it to your Microsoft account.  You'll be able to (try to) launch Sims 4 without reinstalling anything.

If that doesn't help, please let me know what antivirus you use.  Please also run a dxdiag and attach it to a post.

https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/

@puzzlezaddict Thank you for your response. I did the dxdiag last night before the post was made and I have the normal anti virus called Windows Security that comes with Microsoft laptops. I looked into my Steam settings and my family sharing is already disabled. 

Update: I made a new admin user and Sims 4 launched successfully. Thank you so much for your help, you're a lifesaver. Now I wonder why did I have to make a new user to get it to work?

@Simtinee  The fact that the game worked in a new admin account means that the problem is contained to the old account, which is of course a good thing.  There are two main suspects: OneDrive and broken permissions on the user folder or one of the folders it's in.  For OneDrive, try pausing syncing, which you can do by right-clicking the cloud icon in the lower-right corner of the screen.

For broken permissions, the takeown command can reset them.  Please see this section of a guide I wrote for a different error for how to run the command, and for another command you can try if takeown doesn't help:

https://answers.ea.com/t5/PC/CURRENT-ISSUE-Sims-4-already-running/m-p/13276380#permissions

Hi again, 

So as part of my many tries to resolve the issue with Sims 4, I disconnected my OneDrive from my laptop as I've heard that can create many problems for people. My drive hasn't been connected for quite some time now. 

I tried the takedown command but now I'm not sure what I've done as the prompt is confusing because it says that the gaming user I created to launch sims now owns my main user's documents folder. I'm pasting the prompt here:

Microsoft Windows [Version 10.0.22621.3672]
(c) Microsoft Corporation. All rights reserved.

C:\Users\desti>reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v "Personal"

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
Personal REG_SZ C:\Users\desti\Documents

C:\Users\desti>takeown /F "C:\Users\desti\Documents"

SUCCESS: The file (or folder): "C:\Users\desti\Documents" now owned by user "DESLAPTOP\Des Gaming".

C:\Users\desti>

@Simtinee  You'd need to run the takeown command from your main account, not your new one.  The idea is to login to a given account, use the first command to find the full path to Documents, and then immediately run takeown from that account using the file path you found.  You can still do this second part; the command should work fine once you're in the right account as long as that account has admin rights (which it should already).

That why I'm confused. I ran in under my main account but somehow it gave my main account's document ownership to my gaming account if I understand the prompt correctly. Desti is my main and DesGaming is the second account I made.

Update: I'm deleting the gaming account and will try to see what happens

@puzzlezaddict @8bitNifty I've officially tried everything according to the articles provided to me. I even got a malware app to delete any possible viruses (I had 12 from Chrome). I can't get Sims 4 to open. I officially give up. Thank you for all your help.

@Simtinee  There's no reason you can't play Sims 4 in the new admin Windows account.  It might be inconvenient, but it's also simple to transfer your saves and other content to the new account and pick up where you left off.

@8bitNifty  Please describe your own issue in more detail, including a screenshot of any error message you see and when it happens.