User blog comment:Lost Labyrinth/Tips on improving the visual quality of TS3 with minimal performance impact/@comment-24611888-20140301145149/@comment-2201555-20140302151734

So you've still failed to read my instructions.

The d3d10.dll won't work because The Sims 3 is strictly a DirectX 9 game and has no support for DirectX 10. You can't just magically use DX10 libraries with DX9 titles, because the game has been designed to call DX9. While developers of other titles have patched in DX10/DX11 support for their games before, it never happened, nor will it happen, with The Sims 3, nor is there any reason for EA/Maxis to do so.

I've already told you to try reinstalling DirectX if you want your system-wide Direct3D 9 libraries fixed. If that doesn't work then your only hope is to reinstall Windows. You should have thought about this before you conjured up an idea from nowhere that blindly replacing system files was a good one.

Don't touch anything in the Windows install directory unless you want to kill your OS. The d3d9.dll goes in the same directory as the executables for The Sims 3. If you don't know where it is, either look through your Program Files or Google it - I'm not spoonfeeding you.