Reformat if what the other humans say about how to fix this didn't work or made it worse.
Trust me, blue screens are a computer's first sign of cancer, Do not get it radiation tested, or it will die. That's how i lost my brother, he lived inside of a XBOX and used a MAC OSX10, He died of radiation cancer after he got his first bluescreen
(How did a XBOX MAC THING get a bluescreen I DON'T KNOW.)
(Seriously though? I recommend to put your files inside a Flash drive, and reformat, that's what I do when everything DIES.)