How to protect Microsoft Excel 2013 files with password?
There are two ways to protect Excel workbooks to encrypt with passwords.
First: If you just want to lock it down with Encryption, follow this process.
1. Click on the “File” menu button on the top left corner of Excel Sheet.
2. Click Info -> Protect Workbook -> Encrypt with Password.
3. Enter a strong password when prompted. Click OK and then Save it.
Second: If you want to prevent Excel workbook to modify, follow this process.
1. Click on the “File” menu button on the top left corner of Excel Sheet and then Save As.
2. On the bottom of the Save As dialog, click Tools. On the Tools menu, click General Options.
3. A dialogue box will prompt. Under File sharing, type password to open and password to modify.
4. In the Confirm Password dialog, re-type the password.