Atomic RAR Password Recovery is a software designed to restore the password for the archives created by WinRAR. Due to the structure of the RAR-file, encryption in RAR is quite strong, so the password can not be found instantly as it takes a lot of resources. The speed of the password search depends on the archive version. Password restoring procedure for RAR 2.xx archives is much faster then for the RAR 3.xx ones.
Brute-force attack generates the list of passwords using all available symbols and checks them one-by-one. It's slow method, but only it can guarantee the password recovery. Brute-force attack can be used if your password is less than say 5 characters, otherwise, password recovery can take months! In fact, the longer your password is, the longer it takes (exponentially)!
Hey! If your password is a known word (not name or so) then there is a way out. You should use Dictionary attack. This method could speed up things to about 1/2 an hour. You can get Dictionaries (word lists) on the Internet. Under the Dictionary attack all provided passwords are checked.
Atomic RAR Password Cracker has a friendly user interface. It has a wizard which helps you to find the password in the fastest way. The program is able to save a current state (you can interrupt the program at any time, and restart from the same state later). Estimated time calculator allows you to configure the program more carefully.
More information from program website