The preferences dialogue box allows you to change certain aspects of the application's behaviour. Click on the Preferences button:
in the upper right-hand corner of the GUI to access the preferences dialogue box.
System and User preferences
There are two distinct types of preferences in PFClean, System preferences and User preferences.
System preferences apply to the local machine. These settings are identical for all PFClean users on this computer.
User preferences apply to the current user. Each user can have their own preferred settings on the same machine.