: Paste the raw registration data provided by your source into the empty document.
: Open Notepad (Windows) or any basic text editor.
If you meant creating a text "comment" or description that appears when someone opens your .rar file, follow these steps:
: Copy this newly created rarreg.key file and paste it into the WinRAR installation directory (usually C:\Program Files\WinRAR\ ). Adding Text Notes Inside a RAR Archive