So You've Lost Your Password
One of the more frequent questions in the newsgroups in what to do when a password has been lost. The following sites have products or add-in modules that claim to be able to break Excel passwords. I have never used any of these products, so these are not recommendations or endorsements. These URLs are provided only as a public service.
A comprehensive suite of password bypass software is avaible from Passware
Remember, you should only recover password protected files that you have a
right to view. Opening up files that belong to others is unethical at
best, and may be a violation of your license agreement or of copyright