If when you try to start a program, you receive an error message This program can’t start because xinput1_3.dll or d3dx9_43.dll is missing from your computer, here is a solution that you can use to fix both the problems. These types of problems mainly occur when you try to start a game. Some game’s setup files come with the DirectX installer file that gets installed automatically along with the game files. If it doesn’t get installed for some reason or if the said file become corrupted or go missing, you receive such error messages.
DirectX helps users to play multimedia files or programs on Windows computer by accelerating the hardware. If DirectX files go missing or get corrupted, such issues can arise.
xinput1_3.dll or d3dx9_43.dll is missing
The leading cause of both of the problems is missing DLL files of the DirectX installation.
If you are using Windows 10 or Windows 8.1 that has DirectX 11.1 and DirectX 12, you should run the Windows Update tool. If any update is pending, do install that and check whether it solves the issue or not.
The way of solving d3dx9_43.dll missing error is exactly same as above. You need to download DirectX End-User Runtime Web Installer to your computer if you have DirectX 9, or if want to update the existing DirectX installation to v9.0. You need to also run Windows Update.
Update Graphics driver
To fix either of the problems, you may update your Graphics Driver. You can either check out the official website or the graphics card management tool that most of the manufacturers provide with the graphics driver.
Hope these solutions work for you. If not, you can always try to re-install the software after removing it completely.