How to Encrypt an Excel 2007 File

1. Open the Excel workbook you want to encrypt.
2. Click the 'Microsoft Office' button in the top-left corner of the screen.
3. Place your mouse cursor over the 'Prepare' entry on the left side of the menu to bring up its options. Click 'Encrypt Document' on the right side of the menu. A password pop-up window will open.
4. Enter a password for the document. Make sure you can remember it since you will not be able to recover the spreadsheet if you forget it.
5. Click 'OK,' re-enter the password and click 'OK' to close the window.