Can't launch the game "Service initialization failed"

d0fdef48c2338f24  If you're going to do another clean uninstall, I'd suggest reinstalling both the EA App and Sims 3 using a new admin Windows account.  Make it local, as in, don't link it to your Microsoft account or any email address.  If this works, you may be able to play in your main account too, depending on the original source of the error.

Sorry, I meant that it's installed via the EA app, not Origin. Getting a bit frustrated with this. 
I tried doing the clean uninstall according to the link you sent - the problem remains. Will try it again and see if it works. 

Any other ideas? Thank you again for your help! 

d0fdef48c2338f24  The simplest approach here is to do a clean uninstall of Sims 3, as described here:

[Read First] Running Sims 3 in Windows | EA Forums - 8323446

When reinstalling, you'll need to use the EA App, not Origin, which has been sunset in Windows for almost two years now.

Hello! 

I have the same problem and it's driving me crazy. I checked the values in my folder under HKEY_LOCAL_MACHINE > SOFTWARE > WOW6432Node > Sims and I only have 8 values in the folder. Can you help me? 

The game is installed via Origin if that makes any difference.
And I am really bad at anything computer-related so explain to me as if I were 5 years old. 

Thank you in advance! 

Update: I had given up on trying to launch the game, but after updating my graphics software and reinstalling everything it finally worked. I've been playing for two days without any problem.

DannyPleasant  That's good but also a bit disappointing, in that a missing entry would have explained the problem.  At any rate, please uninstall Sims 3 with Revo Uninstaller (the free version is fine).  While you're at it, uninstall the EA App as well, using the Intensive scanning method.

Reinstall the App, and create a new folder on the root level of the drive of your choice.  For example, C:\Games is fine, but not C:\Program Files\Games.  Install Sims 3 into that folder and try to play.

If you use a third-party antivirus, please disable it (temporarily) while installing the game, and don't reenable it until you've tested once.  As long as you don't do anything else at the same time, your computer should be safe.  If you can play, you can reenable the AV, and set exceptions for TS3.exe and Sims3Launcher.exe.

Ok, I checked HKEY_LOCAL_MACHINE > SOFTWARE > WOW6432Node > Sims and I have nine values, there's also a sub-folder called InstallOptSelect.

Under HKEY_LOCAL_MACHINE > SOFTWARE > WOW6432Node > Origin Games I have a folder called sims3_dd, with three values: (Default), DisplayName, and Locale.

DannyPleasant  I don't want to see the actual entries, just compare the ones you have with mine so we can see if you have duplicates or are missing one.  Click Windows key-R and enter regedit in the run box, then expand this:

HKEY_LOCAL_MACHINE > SOFTWARE > WOW6432Node > Sims

You should see an entry for "The Sims 3," with nine values if you click that folder.  Please don't share the actual values (Data), but if you see fewer, post the names so I know what's missing.

I also have a number of entries under ...WOW6432Node > Origin Games, but I'm not sure whether those are supposed to be there or are left over from when I installed the game through Origin.  Please check there too and let me know what you find.  At least one folder may have random numbers for a name, so be sure to click any folders you see to check them.

Thanks a lot. I installed the game through the EA App, and I've never installed any packs. How can I show you my registry entries?

DannyPleasant  The service initialization error is typically related to missing or broken registry entries.  It doesn't have anything to do with .NET Framework 3.5 or the Alder Lake issue, so you can put aside those ideas (not that they were bad ideas, just not worth spending any more time pursuing).  What kind of install is this?  I'd like to compare your actual registry entries with what you should have, but they look different for each type of install.  And let me know whether you ever installed any expansion or stuff packs that you later removed.