How to Password Protect Excel 2007

1. Open your Excel document if it's not open already.
2. Click the 'Office' button in the upper left corner of the window.
3. Highlight 'Prepare.' A list of options will appear on the right.
4. Click 'Encrypt Document.'
5. Type any password of your choosing into the 'Password' text box. The password can be any length up to 255 characters. Longer passwords are more secure because they're harder for people (and computers) to guess, but a more complex password may be more difficult to type and remember.
6. Click 'OK.' Retype the password in the confirmation window that appears.
7. Click 'OK' and save your password-protected Excel file.