Windows 11 includes the latest DirectX Runtime , but it does not always include the full complement of optional "side-by-side" technologies from the legacy SDK. Older games specifically look for these legacy files (like d3dx9_43.dll ) and will fail to launch if they are missing, even if you have a more advanced version like DirectX 12. How to Install DirectX 9.0c on Windows 11

Do not download DirectX from third-party "driver update" sites. Only use the official Microsoft link.

Windows 11 includes modern versions of DirectX (DX11 and DX12) by default, but it does come with the full library of legacy DirectX 9.0c files required by many older games. To run classic titles like Blur or Icewind Dale without errors, you often need to manually install the legacy runtime components. How to Get DirectX 9.0c on Windows 11