Windows operating systems include a "DirectX" diagnostic tool that will test the highest version of DirectX your video card can support. Supporting a higher version means your video card can produce higher quality graphics. You can also refer to the documentation that came with the video card -- it will list the highest "DirectX" version supported. Windows applications that use DirectX 10 (typically games) will often disable DirectX 10 options in their video settings if your video card doesn't support the feature.
Press and hold the "Windows-R" keys on your keyboard.
Type "dxdiag" in the text field, and then select "OK."
Wait for the program to finish checking your hardware, and then click the "Display" tab. You will see a label called "Version" under the "Drivers" heading. The number listed is the highest version of DirectX your video card supports.
Click or tap "Exit" once you've finished.