Lost a password to an important Word or Excel file, can't find it, and figure the file may be lost forever? There's a chance that you may be able to recover it. Advanced Office Password Recovery Home ($49, limited demo) aims to crack passwords for Office and Excel files so that you can open and use them.
To recover a password, run Advanced Office Password Recovery Home, select the file, and tell it to go to work. It begins by checking previously found passwords and passwords in the computer's cache, and then moves onto more sophisticated dictionary and brute force attacks. For simple passwords, for example of four letters, it worked nearly instantly. Longer passwords took several minutes to crack.
In my tests, I found that Advanced Office Password Recovery Home cracked all the passwords I threw at it, until I started using very long, complex ones, for example those of several dozen characters. At that point, it balked and told me to choose more complex methods of attack built into the program, but without saying which to use, or how to use it. But without a background in encryption and password-breaking, I was unable to figure out how to set the options for Brute Force and Dictionary attacks to crack the password. Still, most passwords will most likely be short, so you will likely not run into that problem.
Note: The trial version of Advanced Office Password Recovery Home will recover passwords only of five or fewer characters. If you want to recover longer passwords, you will have to pay to register the program.