I attempted to run a new game software today (Civilization V) and I received the error:
I took the following actions:
1. I googled the dll file. It is related to DirectX.
2. I ran dxdiag on my computer. It assures me that I am running DirectX v. 11 and no problems were found.
3. I located the DirectX installer on the DVD. I attempted to install DirectX. The installer assured me that DirectX was up to date. No changes made.
4. I attempted to run the program again, and received the same error.
5. I searched my computer for the missing file. There is no file d3dx9_42.dll on my C drive.
6. I came here.