Remove "Set Optimal Settings" message

How can I get rid of the message that pops up sometimes when starting Call of Duty 4 – Multiplayer?

Your computer appears to have changed since the last time you ran Call of Duty 4: Modern Warfare.
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.

I have tried these different solutions, none of them works:

• Remove the lines corresponding to the message in the C:Program FilesActivisionCall of Duty 4 - Modern Warfarelocalization.txt file:
  
• Make the config_mp.cfg file flagged as read-only (it was originally).
• Make the config_mp.cfg file not flagged as read-only.

I have a sense that this message is linked to the sys_configSum variable located in the config_mp.cfg file, because sometimes this variable is equal to "0", and some other times to "4379996", but I can’t figure why it changes.

Any other ideas?

PS: I do not use Steam.
PPS: The config_mp.cfg file is located under C:Users[user]AppDataLocalVirtualStoreProgram FilesActivisionCall of Duty 4 - Modern Warfareplayersprofiles[profile] for me.