Re-registering software problems

I'm trying to re-install some software (modul8). I have my serial and challenge codes saved from last time but when I try to re-install it just keeps trying to register its self. I wondered if there is some preference file somewhere that modul8 keeps checking.... I have deleted the com file in the preferences folder for modul8 but is there anything else I can try to be sure.

thanks.

Get a program called AppDelete. It'll take care of every file that has to do with the app. Empty the Trash and then install the program again. It'll be as if you started from scratch.

tried that app but still the same problem. I tried installing it on another macbook and it registered (offline) fine. Is there some other preference file or registry(recent windows convertee here) I can delete?