Applications :: Office 2008 Trial Expired?

I installed the 2008 trial Office for mac, but after a few days and 1 use it tells me that the trial has expired. I have tried removing it as well as reference to it in receipts and library-preferences, but when I reinstall I get the same message. I downloaded another trial code, but it still tells me that it is expired. Where does mac store this information, or what other file do i need to remove to actually use to 30 day trial.