If a password is too complex to be successfully discovered via the 'brute-force' method, a second option remains. Since Word documents (pre-Office XP) are encrypted using 40-bit encryption, it is actually more efficient to try every single possible 40-bit numerical key than to attempt to guess a long and complex password, since the number of variables is smaller.

This method still takes an extremely long time, regardless of how complex the original password is, but it is virtually guaranteed to eventually crack the protection. Unlike the 'password guessing' method, this procedure removes the password protection entirely. Word for Office XP uses a much greater level of encryption by default, and thus the 'key matching' method does not work for Office XP files.

The GuaWord program can be used to decrypt word documents by the simple expedient of trying every possible numerical key combination until it finds the correct one. The password protection is then stripped from the document. This does take a while, though it will almost certainly work. You will be letting it run for a few days, however. It works on office 97/2000 Word files and uses the command prompt.

To use GuaWord:

First, make a backup of your file. This software actually strips the password protection from the file, and it is possible that the file may be corrupted in the process.

Extract the Guaword.exe file to a folder on your hard drive. Open the command prompt by going to the start menu > run > and typing in 'cmd'.

Navigate to the location of the executable file.

Type 'guaword (yourwordfile).doc' to start the decryption process. Depending on the speed of your system, decryption will take several days. Unfortunately, your system will be rather busy while you are running Guaword, so consider using an alternate computer in the mean time. The same company has a paid version available which allows you to pause and resume the process.

There are several other commercial packages available which do the same thing, so if you are looking for a bit more efficiency than Guaword can offer, shop around.

Recovering Password Protected ZIP files, and other compressed files

Compressed files with password protection can be accessed by means of a 'brute-force' password recovery program that checks all possible character combinations to a certain range, or performs a dictionary attack. Since most compression programs are capable of creating various types of compressed files (.zip, .ace, .rar, etc.) most password recovery programs focus on one of these types, irrespective of the software that created it.