Hey everyone, so I got a new computer with windows 11.
I reinstalled my Sims 3 game which works without any problem but when I tried installing TSRW it keeps throwing the error attached in the screenshot.
I honestly tried everything, reinstalling SlimDX, installing the DirectX legacy package from the official Microsoft website, installing the new version of TSRW, installing the old Sims 3 version, but it still keeps throwing this error at me.
If anyone can help I'd be really grateful

Update: Decided to update this thread since I finally found the solution! :D
Apparently the solution was really simple, I needed to remove all my DirectX 9 dll files (the files are named "D3DX9_Number") from my Windows folder (save it in a backup folder!) and run the June 2010 runtime installer from Microsoft's website and it fixed the corrupted dll that was causing the problem, now my laptop can finally retire in peace :')

Now, I know that I got this exact error when I factory reset my PC and... well I can't remember what exactly the solution was, but I at least know there IS one

Let's start with the exact version(s) of SlimDX I have installed:


It should technically ship with the TSRW installer already, but it's possible that if it's redirecting to a modern version it's actually too new.
But if there's no luck there and nobody else recognises the issue in the meantime, I'll dig back through my browser history for when I was banging my head against it myself.

Thank you so much for trying to help <3
I already had the .Net 2 and .Net 4 x86 versions, I also installed the x64 version now but still the same error.
I'm starting to think that maybe something got screwed up with the registry keys, but if so, I have no idea how to fix it ^^"

Hopefully someone with Windows 11 may be able to shed some light.
I'd take care with modifying the registry- what made you concerned about the keys?

A couple of basic suggestions:
1. Try installing TSRW to a location outside of Program Files, like a folder you make for it on your desktop.
2. Run the installer and/or the program as administrator.
Those would rule out if the program is just being denied access to the components it needs.

Otherwise, these are the other utilities I installed after the factory reset:
- .NET Framework 3.5 (this one used to be listed as a requirement for TSRW on their old wiki)
- DirectX End-User Runtime Web Installer / dxwebsetup.exe
- DirectX End-User Runtimes (June 2010) / directx_Jun2010_redist.exe
- Microsoft Visual C++ 2015-2022 Redistributable / vc_redist.x64.exe and vc_redist.x86.exe
- Microsoft XNA Framework Redistributable 4.0 / xnafx40_redist.exe
Not all were for TSRW, obviously, but they were all TS3 related- so at the very least, you may skip some trouble shooting for entirely different modding tools in the future

I'm suspecting the keys because I already tried all the steps you mentioned and unfortunately the error message keep showing up, something prevents SlimDX to see that the newest directX 9 is installed.
Right now I'm trying to fix the registry with a post I found on the Microsoft support forum.

I also asked one of my friends to install TSRW on her computer since it also has Windows 11 installed to see if she gets this error as well.
I'm waiting for her to update me, if she wouldn't have the error, I guess I'd just factory reset my computer, luckily it's completely new so it's not like it has important data on it.

Update: So my friend installed TSRW on her computer and it works, so it seems the problem is my installation of Windows.
I'll do a factory reset this week and update if it solved the problem.