This free download provides the Microsoft DirectX Redist Runtime, which is required for many games to play properly. The download is the offline installer, so no Internet connection is required for installation of DirectX.

Installing DirectX Redist will let you fix problems like "d3dx9_39.dll not found", "dsetup.dll error", or "d3dx9_43.dll missing".

You only need to install one set of DirectX Runtimes, they are cumulative, all previous versions are included automatically.

I added a batch file "# install.bat", which installs DirectX without any user interaction, so you don't have to click "Next", "Next", "Finish".

The June 2010 version is actually the newest version available. Microsoft has stopped updating the Redist and newer games no longer rely on the d3dx extension libraries.