Have you received the following error?
To fix the problem manually: go here and follow the instructions.
[Edit: update link with friendlier web installer for DirectX runtimes.]
We're trying to figure out why a small percentage of users are receiving this error. The update process should ensure you have everything you need. It may only happen to users running 64-bit versions of Windows. If you have experienced/are currently experiencing this error, please help us out by following these instructions and posting your system info, or at least tell us what version of Windows you are running.Cannot find import; DLL may be missing, corrupt or wrong version
File "d3dx9_36.dll", error 126
To fix the problem manually: go here and follow the instructions.
[Edit: update link with friendlier web installer for DirectX runtimes.]