pref.ini definition, relationships, removal:

pref.ini is a configuration file used to store essential settings of some parasite components. Usually these settings describe standard threat behavior, its functionality and additional features. Deleting such file may help to stop a parasite or disable some of its functions.
The pref.ini file is installed and used by trojan Frenzy.
Please note that the pref.ini file actually may be a fully legitimate part of the operating system or legitimate software. Often parasites use files with unsuspicious names, but malicious functionality. You should always carefully check the file before deleting it. It may not be related with malware, but can be required by your essential programs to work properly.