Hm... yea, rly weird, as I understood it have to be no difference, but I have installed few times with errors, and problems disappeared only after typing "en".
About steps nothing useful to add I thnk:
1)extracting folder from archive to cod4 directory, so installer had path "...\Call of Duty 4 - Modern Warfare\LanguagePack\installer.cmd"
2)runned installer and typed "english"
3)runned cod and in a half of the second menu screen "paused" (no menu music and animations like smoke) + opened windows with error message "Couldn't load image waypoint_bomb"(nothing more).
Reinstalled few times without any changes, and as I said before only after "en" it worked correctly. Btw it's showing error "LanguagePack is not placed in cod4 directory!" if to open with admin rights, if this may be useful...
- Mrozy likes this