What you need:

Conquer.exe
Step One: Close all CO accounts/Windows.
Step Two: Open XVI32 Hex Editor and Click the Open button.
Step Three: Choose to show only *.exe files (By choosing it from the bottom drop box), then go to your CO directory.
Choose Conquer.exe (There should only be one)
Step Four: Search for Text String "English" (No quotes). Change that to "english" (People say that changing it to "chinese" works as well) Notice that this is after "Japanese".
Credits to GraveDigger, I'm pretty sure I got what Text to search for from him.






