Copy and paste this into a file and call it
localization.txt. Place it in your MW3 folder. Or you can verify the game integrity with Steam to get it redownloaded.
Code
english
WIN_CONFIGURE_UPDATED_TITLE
"Recommended Settings Updated"
WIN_CONFIGURE_UPDATED_BODY
"The recommended settings have been updated since the last time you ran Modern Warfare 3.
Would you like the game to configure itself optimally with these new settings?
This is recommended for most people. It will change your system settings but not your controls."
WIN_LOW_MEMORY_BODY
"It looks like you are low on virtual memory.
This can cause the game to run slowly and it may stop completely.
It is highly recommended that you close some programs before running Modern Warfare 3.
Do you want to run Modern Warfare 3 anyway?"
WIN_LOW_MEMORY_TITLE
"Low Memory"
WIN_COLORDEPTH_WARN_BODY
"It is highly unlikely that a correct windowed display can be
initialized with the current desktop display depth. Select
'OK' to try anyway. Press 'Cancel' if you wish to quit."
WIN_COLORDEPTH_WARN_TITLE
"Low Desktop Color Depth"
WIN_COMPUTER_CHANGE_BODY
"Your computer appears to have changed since the last time you ran Modern Warfare 3.
Would you like the game to configure itself optimally for your new hardware?
This is recommended for most people.
It will change your system settings but not your controls."
WIN_COMPUTER_CHANGE_TITLE
"Set Optimal Settings?"
WIN_DISK_FULL_BODY
"Modern Warfare 3 couldn't write a file. The hard drive is probably full."
WIN_DISK_FULL_TITLE
"File Write Error"
WIN_IMPROPER_QUIT_BODY
"It appears that Modern Warfare 3 did not quit properly the last time it ran.
Do you want to run the game in safe mode?
This is recommended for most people.
It will change your system settings but not your controls."
WIN_IMPROPER_QUIT_TITLE
"Run In Safe Mode?"
WIN_ERROR
"Fatal Error"
WIN_NO_STEAM
"Steam must be running to play this game."
WIN_OUT_OF_MEM_BODY
"Out of memory error. You are probably low on hard disk space."
WIN_OUT_OF_MEM_TITLE
"Out of memory error"
WIN_UNABLE_LOAD_DLL_BODY
"Unable to load a DLL. Possibly due to low memory, insufficient hard drive space, or missing DLL files."
WIN_DIRECTX_INIT_TITLE
"DirectX Error"
WIN_DIRECTX_INIT_BODY
"DirectX encountered an unrecoverable error.
Check the readme for possible solutions."
WIN_MSS_INIT_FAILED
"Miles sound system initialization failed.
Make sure you have your sound card's latest drivers and DirectX installed."
WIN_COULDNT_START_PROCESS
"Could not start process"