DirectX DLL errors
There are two completely different things called DirectX here. One comes with Windows and cannot be installed. The other is a set of legacy helper libraries that can, and that is what almost every one of these errors is really about.
You cannot install DirectX 12
DirectX 12 is part of Windows 10 and 11 and is updated through Windows Update. There is no standalone installer, there never was, and Microsoft does not distribute one. A site offering a DirectX 12 download is offering something else.
To check what you have, press Windows and R, type dxdiag and press Enter. The version appears on the System tab.
The legacy files you can install
Games built in the DirectX 9, 10 and 11 era expected helper libraries that Windows does not ship. The DirectX End-User Runtime installs every version of them at once, alongside your current DirectX rather than replacing it.
And the ones that are neither
These belong to Windows itself. If one is reported missing, the usual cause is a mod or wrapper that placed its own copy inside the game folder, not an absent system file.
The rule of thumb
- A name with a version number in it, such as d3dx9_43 or xinput1_3, is legacy. Install the End-User Runtime.
- A plain name such as d3d9, dxgi or dsound belongs to Windows. Check the game folder for a mod, then repair system files.