If you are looking for free software to extract rar files without password then here are two simple tools to open locked rar file archives. Simply download them you might jut be able to extract files from password protected Rar files.
Extract Files from Password Protected RAR Files
Winrar Unlock:-
Unlock locked winrar archive (including SFX) allowing you to modify the content freely. With Winrar archive lock to prevent modification, people cannot change the content/comment in it. Through some patching of few bytes, you are able to modify your archive with ease.
RAR Password Cracker:-
This program is intended to recover lost passwords for RAR/WinRAR archives of versions 2.xx and 3.xx. The program finds by the method of exhaustive search all possible combinations of characters (“bruteforce” method), or using passwords from lists (“wordlist” or “dictionary” method). Self-extracting archives and multivolume archives are supported.
The program is able to save a current state (you can interrupt the program at any time, and restart from the same state later).