"h4xx" Duplicate File Detective?

Ok, here's the deal. This summer i dowloaded DFD and clean out some HDs during the 14 day long trial period.

But now I need to clean out them again. So I runned regedit and deleted all references to DFD, then I installed it again. But it still said that the trial period was over and I had to register yadda-yadda.

Does anyone please know how to make the computer "forget" that DFD was ever installed?

I see. So it's impossible to rid my computer of the countermeasure DFD must've installed?