How to Remove Passwords From Winrar

            A Winrar file contains multiple files compressed into one so as to reduce the size and is done for ease of transport for sending attachments while emailing etc , check List of all File Compression softwares .These files can also be password protected so that no unauthorized person can access the archive's contents . Sometimes it happens that you may forget the password or you may want that zipped file to be made available public so that anyone can access it  , so to get out of hassle , therefore its better that password needs to be removed.
You can do this by creating a new archive without a password .


Open the WinRAR and right click on the RAR file that has the password you want to remove.
Select "Extract Files" from the list of options.
Enter the RAR file's password in the window that appears and select "OK."
This will extract the archive's contents into a folder in the same directory that the RAR file is in.
Now right click on the New folder , ie the one which is newly created  and select "Add to Archive."
This tells WinRAR that you want to take the files in the folder and place them in a new RAR file.
Select the "OK" option in the window that appears.
Now the files in the folder then will be added to a RAR file.
When WinRAR finishes creating the archive file, you can access it without password protection.

UPDATE:

The above post is useful only if you know the password and want to remove it , but if you dont know the password then its practically very very hard and almost next to impossible !
You'll need an archive password-cracking program and that doesnt come free

• www.brothersoft.com/.../remove-win-rar-password.html
• www.rarpasswordcracker.com
• www.sharewareconnection.com/rar-password-recovery.htm

Here are above links , that may crack password of RAR file and help you ,
these doesn't come free , so you need to purchase these shareware !
Go to a website where you can download a program for breaking a password on a RAR file.
Download and install your archive password cracker.
Open this software and  find your file.
Choose the option you prefer in the "type of attack" box.
The software will go through letter combinations,  to find your password.

Note: It may take a hell lot of time !