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.

The Excel file may say it’s locked if the user who shared it with you is currently editing the document. It can also be because the Office app running in the background has already opened the file.

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.

Sending Excel files containing crucial financial and business data has risks. To add a layer of protection, you should learn to password protect an Excel file.

Here is a tutorial to lock or hide only the formula cells in an Excel workbook. You can also lock formulas in all worksheets in a workbook.

Microsoft Excel lets you embed content from other applications, including PDF files. You can embed a PDF file into a cell of an Excel worksheet and then use Excel's security features to lock the ...