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.

A recommended approach to secure your most private documents — whether it’s a PDF, Word file, or Excel spreadsheet — is to lock them with a passcode. While this does help keep sensitive ...

You can make Excel always open old spreadsheets in Protected View. Enable or disable Protected View using in-built setting, Group Policy, Registry.

A recommended approach to secure your most private documents — whether it's a PDF, Word file, or Excel spreadsheet — is to lock them with a passcode.