It may seem like somewhat of a detour, but demonstrating as a first practical example that all problems are recoverable can serve as a big confidence boost, helping people feel more confident messing around with all the other little things and being more comfortable potentially breaking them. For didactic purposes, I would split the exercise into two sections.
1: Place some "precious files" (some funny memes) on a sacrificial machine, then render it un-bootable by some means (deleting the EFI bootloader, corrupting / deleting some OS files, etc.). The purpose of the exercise is to prepare a bootable USB media and demonstrate that file recovery (under mundane circumstances, when the computer simply stops booting) is not some wizardry requiring the expertise of computer forensics experts. All you need is the ability to point a functioning OS at the filesystem. A second USB drive can be formatted as a destination to place the recovered files.
2: After exercise one, OS re-installation and restoration of the recovered files. While Linux is great, and likely will be a requirement of exercise one, the focus here should be on installing whichever OS the user is comfortable with. The point is to demonstrate that installing an OS and starting from scratch is easy, which is true regardless of if it is Windows or a mainstream Linux distribution. Either way, several tasks from exercise one will be repeated: flashing a USB image, formatting drives, selecting an alternate boot device in the UEFI firmware.
2.1: If using Windows, demonstrate how simple it is to use the MassGravel Windows Activation Scripts, so users understand they never need to worry about what happened to their original installation media or license key sticker as a pre-requisite for OS installation.
I think beginning these demonstrations on PC hardware is a better option than some more locked-down devices like video game consoles, routers, or mobile phones - where the tools are often reverse-engineered / experimental, and mistakes potentially can lead to permanent damage.
The National Education Association votes to cut all ties to the Anti-Defamation League: https://mondoweiss.net/2025/07/the-national-education-association-just-voted-to-cut-all-ties-to-the-anti-defamation-league/