My son was trying to fix a game by following the instructions of a Microsoft rep and in doing so has locked himself out of his Pc. It comes up with the windows screen with a photo of a stork and the icons but no login. Tried safe booting using shift and restart and nothing, used my win10 boot disc and nothing helps. Anyone got a clue what to do, he's panicking a little here. I forgot to mention he was told to temporarily disable are third party apps in msconfig.