The file d3dx9_26.dll is one of many files included in DirectX. Since DirectX is used by most Windows-based games and advanced graphics programs, errors related to this file will usually only appear when using those programs.
How to Fix Missing d3dx9_26.dll File in Windows
Follow these steps in the order they are listed below to try the simpler solutions first.
Restart your computer if you haven't already done so.
The d3dx9_26.dll error could be a fluke or a one-time issue, and a simple restart may fix it completely. This is unlikely to fix the issue, but a restart is always a good first troubleshooting step.
