How do I get DirectX 12 with ATI Radeon HD 4800 Series, Windows 10?

I'm running two ATI Radeon HD 4800 Series video cards on Windows 10. I want to install the newest DirectX. I looked in the diagnostic tool and it says I have Version 10.1. I have gone to Windows Updates and checked for updates, but it says it's up to date. I'm not able to play certain games, since I don't have at least Version 11. Any help would be thankful.

 Press the Window button plus R

Enter this: dxdiag

You should see Direct X  12 at the bottom. It comes with Windows 10.

If it doesn't try updating to Direct X 11 here: http://www.microsoft.com/en-us/download/details.aspx?id=17431

Actually, the previous post is wrong.

If you run dxdiag, the DirectX version reported on the first page is the version supported by your OS - which is 12 for windows 10. To see the actual version that your GPU supports, go to the "Display" tab and look for Feature Levels. It's most likely that the highest level shown there will be 10_0 or 10_1 and not 11_0.

In reality, your GPU does not support dx11, and there's little you can do about it.