Remember that, with password protections removed, anyone with access to your Excel file can open, view, and edit it. If you've decided a password isn't necessary anymore, this likely isn't an issue.

On the right side, select the Open checkboxes for the file types that you want to open in the Protected View. Now, select the Open selected file types in Protected View radio button at the bottom.

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