There are so many causes for this that more details are needed.
However the most important thing (or things) is are you ready to wipe out and start over?
"We only lose what we didn't backup."
Today I find the fast fix is to slip in a new drive and leave the old drive out for later and reinstall Windows. This is your generic catch all repair when working in a vacuum.
My computer restarts itself with a blue screen when I turn it on. It tells me to either restart it again or use other options but when I try to go into the desktop mode, it restarts itself again and I end up at square one. I'm on Windows 10. Can anyone please help me?