Notepad++ - This is the definitive notepad-related software you’ll ever need. Multiple tabs, keeps tracks of lines, lots of features and preferences. One of the most invaluable parts of it, is that you can close it or a update happens or maybe your PC will get knocked offline. You can come back to Notepad++, open it, and everything will be retained.
For Notepad++, make sure you’ve installed the latest version using a download from the official website. Their automatic update feature got hijacked to package in malware within the past few months and the only way to shift to the newer secure update “source” is a reinstall from the site, as far as I’m aware.