I've been sharing this for over a decade and I'll share the link here but note we still don't learn Linux and we don't install Linux. We boot it, fish around with file manager just like in Windows and copy our files out.

BE SURE TO COPY!!! Once your files are safe, then you delete. If you MOVE files and the move fails you might lose files.

Read http://tips.oncomputers.info/archives2004/0401/2004-Jan-11.htm

That's what I use when the OS does not work.

As to the save the OS, I find that when this happens about half the time I have to reload the OS or use the factory recovery which means all files on the drive are gone.