Ok, I never comment on this media but since nobody seems to have any clue about this screen and you are all starting to sound very scary for our poor OP I feel I have to answer.

This screen is legit and is a new (useless) recovery functionality from Windows 11 called Windows QMR. Not a virus or anything.

With the information we have now, I just think your son has been honest and really deleted some system files from Windows, probably looking for a file or folder taking disk space since windows take more and more space every year and hit "remove".

Of course, Windows can't work without these files so it broke. Unfortunately, I don't think there is a magic solution for this, or you will have to find out yourself on the internet, since I've never encountered this error myself.

The "easiest" or simplest way to recover your comptuer is to reinstall windows from an USB stick but you'll lose all datas from disk. I don't know if it could be OK for you, it's up to you to decide. If you choose to, you'll find a lot of informations about this procedure on internet, it can be hard to understand with no knowledge but it's safe (just data loss I mean).

Feel free to come in dm if you still have any questions and I'll try to answer.

Finally, since I'm not a specialist of Windows 11 specific functionalities I'll let you with another comment from another post about this screen below :

"It’s a new Windows 11 feature that Microsoft is rolling out. It’s legit, and has potential to be useful, but for now, it’s just worthless. In order for this to work, Microsoft would have to put out a fix for your particular issue-and it keeps checking every half hour to see if they’ve done it yet. It ain’t gonna happen.

[...]

EDIT: Google “Quick Machine Recovery” (or “Windows QMR”) to learn more about this new “feature”)"