BeyondUnreal's Essential Files Page
COR 1.0 - Download the zip file to your computer and then extract the COR and System folders directly into your UT2004 directory. You will then be asked if you want to overwrite the System directory. Don't worry, we are simply adding a file to it, so allow it to overwrite the System directory. After everything is done extracting, navigate to your COR directory inside of UT2004 and double click the COR-Play.bat.
COR 1.01 - All you need to do is extract this zip into your UT2004 directory. It will ask you to overwrite files, if it doesn’t, you have extracted it into the wrong directory.
