While Windows 8, 10, and 11 include core DirectX components built into the operating system, the June 2010 runtime package was historically essential because it contained specific "side-by-side" components required by older software.
Advanced audio engines used in mid-2000s games.
Unlike modern DirectX versions (such as DirectX 12), which are strictly tied to the OS version, the June 2010 runtime was notable for its comprehensive backward compatibility. It did not merely update the core system files; it installed a suite of specific DLLs that games could call upon independently.
To verify that DirectX End-User Runtimes (June 2010) has been installed successfully:
The standard for Xbox 360 and modern controller support on PC.
Helper libraries used by developers to simplify graphics programming.