OpenFK requires some manual work to set it up fully.
Put the contents of the OpenFK release into your RadicaGame folder.
You will also need to find the Flash.ocx file, OpenFK will prompt you to download a compatible version if you don't have one.
If it doesn't prompt you, you can download and use the FetchOCX.bat utility.
Be sure to run the 'Configure OpenFK.bat' file to choose from some choices!
To use USB support, you will need to have the MegaByte drivers installed.
Enable USB Support in the OpenFK configuration.
Now you can use USB with OpenFK! (customF and USB can work together!)
Please note USB support currently uses a workaround which can sometimes not work correctly.