How to Save a Workbook With a Password in Excel

Password Protect Workbook
1. Double-click on the Excel document to open it up.
2. Click on the 'File' tab at the top of the screen. Select 'Info' from the menu that covers the left side of the window.
3. Click on the 'Protect Workbook' button in the 'Permissions' area of the screen. Choose 'Encrypt with password' from the list of options. Enter in your desired password and click 'OK.' Enter the password again to confirm it, and press 'OK.'
Protect Document Elements
4. Double-click on the Excel file to open it up. Select the worksheet that you want to protect from the list of worksheets at the bottom of the Excel window.
5. Select the 'Review' tab at the top of the screen. Locate the 'Changes' area of the ribbon and select either 'Protect Sheet' or 'Protect Workbook.' Protecting the sheet will allow you to lock down the particular worksheet you are on from any changes. Protecting the workbook will prevent anyone from making changes to the overall design of the document, like adding new worksheets or altering the name of a current worksheet.
6. Place check marks next to the items that you want to allow people to alter. Anything without a check mark will be locked down. If you chose 'Protect Workbook,' do the opposite, as a check mark will signify to lock down that aspect of the workbook.
7. Type in a password into the field at the top of the window. Press 'OK' to continue. You will have to enter the same password again, and press 'OK' again to lock down the document.