.prf

Contains settings and preferences used by the Windows operating system; may also be used by other applications to store program settings; should not be opened manually.

User profile referenced by Microsoft Outlook that contains user information and preferences; includes mail account settings, signatures, references to mail folders, and other settings; when Outlook imports a PRF file, the user profile settings are immediately updated.

PRF files can also be created using Microsoft's Office Resource Kit. The files can then be deployed to multiple systems using the Custom Installation Wizard (CIW) or other maintenance wizard included with the Office Resource Kit.