XLS Padlock is software for Microsoft Excel to copy-protect Excel workbooks. XLS Padlock is directly integrated into Microsoft Excel as an add-in: it works as a compiler that allows you to turn your Excel worksheets into secured applications. You can safely distribute your XLS files, control which user can access your Excel worksheets and prevent copying.
||Free to try
Windows Server 2003 x86 R2,
Windows Server 2008,
||Microsoft Excel 2000 or higher