http://www.avg.com/us-en/rescue-cd-business-edition?ECID=af:cj#tba2
(from a working computer, like your library's) downloaded onto a flash drive, and create a CD disk, or install it on the flash drive. Here is one version of instructions for it:
http://www.techsupportalert.com/content/avg-rescue-cd-90.htm
It starts itself from the CD or DVD drive, or from the bootable flash drive you created. It can't hurt anything. I've used it many times on repairing PCs.
And it's FRee.
I bought a CD of Ubuntu. Now, if Windows refuses to load or hangs up, I can pop the CD in, set the BIOS to boot from it,
and be able to run on Linux until I can fix the W10.