If you have sensitive data you'd like to keep from prying eyes in a Microsoft Excel file, the easiest way to protect it is with Excel's built-in password tools.

There are several options available to you to protect your Excel file with a password. Remember that once you protect the Excel file, you cannot open it without entering the password.

You can have Excel make a spreadsheet in read only format for others, so that people can read its contents but not edit them, or you can enforce other content restrictions.

In Word, Excel, or PowerPoint for Windows, open the file you want to protect with a password, then select File and Info. You should see a Protect option at the top of the next list: Click this ...