DirectX problem

[RedBaron]

I installed my game, Hearts of Iron III: Semper Fi, and i get a missing .dll file error when i try to run it. Im apparently missing d3dx9_40. On atempting to install DirectX 9, i get an "internal system error", so i can't download that, and i have a compressed folder with the d3dx9_40 that i downloaded, but when i try to extract it to C:\Windows\System32 it gives me the error "can not output file C:\Windows\System32\D3DX9_40.dll"

Any help would be much appreiciated,
--RedBaron

[RedBaron]

Hm, for some reason, when i extracted to the desktop, then copied only the .dll file, instead of the whole folder (only containing the .dll file) into my system 32 it worked. . So thanks anyway.