How you can set a password for a Word or Excel document

With Office 2003, choose Save As. At the top of the Save As dialog window there is a Tools option. Click the drop-down arrow adjacent to the Tools item, and choose Security Options. Then enter your desired password in the Password to Open textbox. In Office 2007, the Tools option is at the bottom of the Save As dialog window; from the Tools drop-down menu you choose General Options.