OK, found it. In Notepad, I changed Files Type from txt to All Files, and there it was. Opened it and scrolled down to the bottom and added that code, clicked Save.
Guess I'll reboot now and see what happens.
Say, with Avast 4.8, do I need to manually update? Reason I ask is that I heard an audible message (volume was low and I couldn't quite make it out) saying something about it updating.