Try downloading the extra links at the bottom of the download page or try and search for it in your downloads to see if you already have them.
For some reason, the extra download links haven't been really working for people with Windows 8 and Windows 10 laptops if they're missing DirectX, so they've had to try and find a different site that gives a safe download for the extra download links at the bottom of the page. Not really sure what's going on with it. So if it's the same issue for you, I suggest looking for a version of DirectX that's compatible with your computer.