How to protect Excel-secure files

Do you want to know how you can protect your work in Excel against unwanted persons?

Step by step:

1. To save the file, he must first call the "Save As" dialog.
2. In Excel 2010, next to the "Save" and "Cancel" buttons, there is a "Tools" combo button. After expanding it, please select "General options"
3. This will open a new "General Options" window where you can decide:
   whether to protect the file against opening, or against the changes themselves.

I would like to add that the protection against opening files causes many more difficulties in getting to the data than the protection against changes itself.