on another pc, download the
windows 10 media creation tool and use it to make an installer on USB or DVD
change boot order in bios so USB or DVD first, hdd second
boot from installer
on 2nd screen of installer, after languages, choose repair this pc, not install
choose troubleshoot
choose advanced
choose start up repair - this might fix this problem, will ask for logon info
if that doesn't work, we try safe mode.
boot from installer, choose repair this PC
choose troubleshoot
choose advanced
choose start up options
choose a safe mode there are 3, it doesn't matter which
PC will hopefully load into safe mode, you don't have to do anything here, just restart and see if its fixed.