"The program can't start because d3x9_26.dll is missing from your computer" due to one of three reasons: Software Overlap:

While its name is designed to mimic a standard DirectX file, the naming convention is incorrect. In almost all cases, this specific file is a component of a software crack, a "no-CD" patch, or a game mod loader. While often harmless in the context of gaming, antivirus software frequently flags it as suspicious due to how it manipulates other programs.

If your game is looking for d3x9-26.dll but you have d3dx9_26.dll , Windows will recognize them as the same file. Your game will continue to show an error.

A
A
ABC
0dB