As noted above, Known-plaintext and Guaranteed WinZip attacks try to recover the encryption keys first. Once they're there, the archive could be decrypted so no password is needed. However, these attacks also attempt to search for passwords that are up to 10 characters long.

If you already have the encryption keys and would like to recover the longer password, select this attack from the Type of attack box. Enter the keys in the Plain-text tab, and set other options such as the character set (Range tab) and password length as if you were configuring the Brute-force attack. The recommended minimum password length is 11 (ARCHPR had already tried the shorter passwords), the practial maximum value is 15 to 16 characters, depending on the character set.

There are specific consideration regarding the Start from parameter. There is no need to recover the first 6 characters of the password since they're calculated based on the "tail" of the password (seventh character and up). So the starting password should start with 6 asterisks, and the meaningful positions start with the 7th character. The program starts to search for correct combinations from the end; for example, for 11-character passwords containing small letters, the order is:

******aaaaa

******baaaa

...

******zaaaa

******zbaaa

******zzaaa

...

******zzzzz

Please take that in mind when selecting the starting password manually.