COD 4 DX9 installation required on top of DX11 ?

OK, I'm running Win7 7201 64-bit. I installed COD4 1.7 last night and when asked about installing DX9 I selected "No" since my Win7 has DX11 installed.

When I try and start either single or multi-player I get an error dialog that reads:

"The program can't start because d3dx9_34.dll is missing from your computer. Try reinstalling the program to fix this problem."

I note on my old XP partition that d3dx9_34.dll is installed in C:\Windows\System32.

I get the impression that I HAVE to install DX9 even though I already have DX11 installed ?

Does this make sense ?

Will installing DX9 cause any known conflicts with DX11 ?

Is there a DX11 compatibility pack required or something ?

You have to run the DX9 setup to get COD4 to work. It will not over write any of the dx11 stuff just update and add the dx9 items the game wants in order to run.

Thanks Xeno... I'll run the web updater tonight and give it a whirl.

yep, I ran into the same thing, re-istalled with DX9 and worked perfectly afterwards.

Similar question here.

Windows 7 comes pre-installed with DirectX 11, and dxdiag shows that.
Now, if we install DirectX9 , which version of DirectX will dxdiag show?
How does this multiple version of DirectX works?

Installing DX9 March redist solved the problem as several folks pointed out.

I was able to play single-player with no issues.

Multi-player - within about a minute of joining a server I got kicked for the "Unknown API" function problem. Boy I hope someone fixes that soon!

I had no issue playing the following games with the default DX11. I didn't installed DX9c when prompted by the game installer.

Ghost Recon 2
LFS (Live For Speed)

I haven't tried other games yet.

@ Sapam
The Dxdiag will show Direct X11, running the dx9 setup just adds the files that older games want. The system keeps the newest files and just adds the older ones into its database.

@ RustyFalcon - if you are running any build above 7137 you will get the unknown API and will until Windows 7 is released due to PB stance on beta builds. The reason 7100 works is because its a RC and they have updated the PB system to include its API layers. There is some new layers added to 7137 and up so it gets kicked. Once Win7 is RTM they will update again fixing this issue.

I had the same problem, didn't install DX9 with COD4 install. I however have COD4 loaded on an XP drive in the same pc, I just pulled the missing .dll from that computer and put it in the correct directory. It launches fine now. Can't play online tho without the pb updated. Sux, I would love to play and see how its working for more than a minute.

OK, here's the thing. Windows 7 comes with DX11. It's back compatible with DX9 and 10, which means that it has DX9 and 10 libraries. When you install windows - it comes with outdated libraries, so in order to play newer game you have to update them. So basically, you are not installing DX9, but updating already existing DX9 libraries.

Whenever you're installing a new game, always make sure to install DX update that comes with it.