As a former computer service technician, we used Ubuntu Live USB and DVDs (yes it was a long ago) a lot.

I remember something happened to my family's Windows computer once. A system file had gotten corrupted somehow so it could only boot into the repair utility, which, naturally, couldn't repair the file.

The solution I found on Google was to put in the installation disc (I think it was Windows 7?), run the disc at startup (by switching the boot order in the BIOS), and fix it using Command Prompt on the disc.

Windows' own diagnostic tool included with the OS couldn't fix the problem. Only the disc could. It was pretty fortunate we still had that thing. Until then, it had just been sitting there collecting dust.

Windows lacking tooling to fix issues caused by its own malfeasance was what made my switch to Linux permanent. I used a LiveCD to fix file system issues that Windows had no tools for unless I wanted to pay thousands for janky third-party tools. Once I did that and recovered most of my lost data, I thought long and hard and just said "fuck it, I'll use Linux".

None of my family will run Linux, however, on my recommendation. I can cope with Linux's ... selective set of user friends. They can't, and I'll be damned if I turn into free tech support.