Password Protecting an Entire Workbook

• 1). Click on the "Review" tab in Excel 2007 (or the "Tools" menu item in Excel 2003 or earlier), and then select "Protect Workbook" from the menu that comes up.
  
  
• 2). Click on the check box that says "Structure" in the dialog that comes up.
  
  
• 3). Enter a password into the "Password (optional)" box. You will be prompted to confirm the password.
  
  
• 4). Save the workbook. Then close it.
  
  
• 5). Open the workbook. You will be prompted to enter a password before being granted access to the workbook.
  
  

Password Protecting A Worksheet

• 1). Place your mouse cursor over the tab of the worksheet you want to protect.
  
  
• 2). Click with the right mouse button; a context sensitive menu will appear. One of the options will be "Protection."
  
  
• 3). Enter the password you want a user to enter before he can modify the contents of this worksheet. You will be prompted to re-enter the password to confirm it.