If you’re running Windows 10 or 11, your system has DirectX 12 and basic DirectX 9 support (via the D3D9 runtime). But those helper libraries? Missing. And older games rely on them absolutely.

Most of us click “Next,” let it run, and forget it ever happened. But here’s the thing: that specific June 2010 redistributable package is still one of the most important pieces of compatibility glue in PC gaming. Let’s talk about why.

That said: It’s not a performance booster or a “tweak.” It’s a compatibility layer.

The DirectX End-User Runtimes (June 2010) is a strange artifact: a decade-and-a-half-old installer that remains genuinely useful. As long as developers keep shipping games built on DirectX 9-era toolchains, and as long as Steam and GOG keep repackaging those classics, that little gray setup window will keep appearing.

If you’ve ever installed a PC game from the mid-2000s to early 2010s—think Bioshock , Mass Effect 2 , Fallout: New Vegas , or The Witcher 2 —you’ve probably seen it pop up without a second thought: a small gray window titled “Microsoft DirectX End-User Runtimes (June 2010).”

First, a clarification. This is DirectX 11 or DirectX 12. Those are modern API versions built into Windows 8, 10, and 11. Instead, the June 2010 package is the final cumulative redistributable for the legacy DirectX 9.0c runtime.