IW3MP.EXE won't start with COD4X installed

I have the CD retail version properly installed and patched to the latest version 1.7, I’ve also installed the latest COD4X version.

The original multiplayer exe file the one that it says iw3mp.exe opens (not related to COD4X) but after I install CoD4X my game doesn’t launch after the splash screen and it force closes itself, there was a way before to get it working by keep opening the same multiplayer exe file several times in a row until it opens but now it doesn’t do that and it automatically closes itself after the splashscreen, It doesn’t even show any error messages.

Uninstalling CoD4X makes the game’s multiplayer exe launch fine, but there is no sense to play without CoD4X.
Even older versions of COD4X doesn’t work.

I know about that thing with Stereo Mixer, but it does not change anything and I have my graphics driver updated to the last build.
Any help would be appreciated thank you please it’s never too late.