You need to upload all files (from FILES dir), then import product.xml, (from PRODUCT dir), then if you need from LANG dir english.xml. Then, in usergroup permissions set what you want for each usergroup, and from Settings for Chatbox you need to set everything - "Activate the chatbox" must be YES

and "Position of the chatbox...." set to predefined option to see is it works.
If works to all of us, must work in your forum