Before installing DirectX on your PC / laptop it will be nice if we check first if there is already DirectX installed, which DirectX & what kind of DirectX ? In addition, you must know about the components used. on your PC / laptop that support which type of DirectX ? Please do not install the DirectX that not supported by your PC / laptop.
To find out the installed DirectX on PC / laptop, please go to the Start Menu on the screen & type RUN in the search field -> select RUN application. Or you also can directly press the WINDOWS icon on keyboard + R, it will be immediately lead to the next step.
Next, type dxdiag in the field then press OK button. The DirectX Diagnostic Tool popup screen will now appear, you can see the various type of components installed on PC / laptop. And of course you can find the installed DirectX at dipped bottom.
Have a little confusion ? Check this video tutorial, may helps you out.