I had the same problem in the past and I solved it with a software.
But before I give you the solution that I found, you must know some
At the moment there isnīt known method to extract the password from an
protected zip file. The only available way to recover it is using a
"brute-force" attack. Undocumented features of ZIP files provide a
great time reduction while searching the password with an appropiate
software and the right settings.
Now we can start to recover the password.
There are a lot of password recovery software, but I will recommend to
you the ones that I consider the best.
First the software that I use:
- Advanced Archive Password Recovery (for ZIP, ACE, RAR and ARJ files)
Four programs in one -- an ultimate tool to recover lost or forgotten
passwords for ZIP (PKZip/WinZip), ARJ, RAR and ACE archives. Supports
the customizable "brute-force" attack, effectively optimized for speed
(for ZIP, up to ten million passwords per second on Pentium II);
dictionary-based attack, and very fast and effective known-plaintext
and guaranteed WinZip attacks. Multilanguage interface is provided.
Using this software is very easy:
1-First you must choose the file to unlock.
2-Select the type of attack (usually brute-force.
3-Range tab: select type of characters used in password.
4-Range tab: select range (if you know or remember that your password
has four or more characters and it starts with "nick" you must put
nick in the start from box to accelerate the process and put nothing
in end at box).
5-Lenght tab: select the estimated lengh of password.
6-Click on Start Button and wait
If the length of the password is more than seven characters it could
be take more than one hour to find the password, and closer you set
the length, the range and the types of characters used faster you can
unlock the file.
For example to find the password "jhonny" (without quotes)it takes a
little less than a minute, starting with no range length from 3 to 8
characters and only small latin chars (a-z). If you range it with
START FROM "jhaaaa" (knowing that the password has six chars) it takes
This software has a trial version with limitations (maximum 5 chars in
password), you can buy the registered version for $60.
- ZIP Password Recovery Processor (only ZIP files)
It is a very good option for only $30, but works with ZIP files only.
- Zip Key
You must register paying $45.
You also can send the files to companies which will do the job for
you. But the price of one password is closer to the price of the
- Password Bully
Specialize in recovering lost or forgotten passwords.
- Alpine Snow
Online Password Recovery Service.
In both cases you must send the files to the companies and then they
will try to find the password, only if they can do it you must pay.
If you more information related to the password recovery:
ZipUnlock.com (A guide to recover your passwords)
Open Directory - Computers: Security: Products and Tools: Password
I hope this will help you