Audacity is an easy-to-use, multi-track audio editor and recorder for Windows, macOS, GNU/Linux and other operating systems.

is an image viewer, editor, organizer, and converter program for Microsoft Windows. It can also play video and audio files and has some image creation and painting capabilities. IrfanView is free for non-commercial use

Notepad++ is a free (as in “free speech” and also as in “free beer”) source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment.