Have you ever forgotten your workbook protection passwords?
This tool has been available from this site since the days of Excel version 5 and has helped thousands recover their work, for free.

This tool will in a relative short time find a password capable of unprotecting the locked workbook and/or worksheets (this password will probably not be the same as the original password).

Have you forgotten the password you used to protect the file itself from being opened?
This tool can help you find this password too, but this will probably take a very long time.
This tool is not capable of unprotecting any VBprojects in a workbook.

Excel 2007 or later version:
After unzipping the add-in and opening it you will find a new menu item in Excel in the Review tab, where you also find some helpful information about this tool.
Click here to download the Excel 2007 - 2010 version.
Updated: 2015-10-27 Requires: XL2007 File size: 190 kB Protected project

NOTE! Excel 2013 or later version:
The workbook/worksheet password protection algorithm has finally improved in Excel 2013, and this tool will no longer be very effective in finding the protection passwords any more.
You can try to save a copy of the workbook as an Excel 97-2003 workbook and then try to find the missing password.