The free version of FastDictionary 2007 (that you can get in "Download" section), is 100% functional and includes all dictionaries available in the registered version. The differences are:
In the free version, the opening screen shows a button offering the registered version and you need to click "Start" to access the dictionary. The registered version don't show this buttons and you start using the dictionary instantly.
In the free version, exists an area, below the translation box, where banners are shown. In the registered version, this area doesn't exist, so FastDictionary uses little space in the screen.
Main reasons to register your FastDictionary 2007...