I HAVE A BIG COMPUTER PROBLEM?

So I have a Lenovo Flex 15. Last night I was in the middle of playing GTA V when I shut the lid to get a drink. When I tried to turn my computer on it was very slow and when I logged back in the whole system crashed. I left it over night to see if would fix itself but it now says "Phoenix Secure Core Technology Setup". I'm very confused. I looked online and it says to use CMD but I have no clue how to find it.

Please Help!

Added (1). *THE LAPTOP DOSNT TURN ON ANYMORE IT GOES STRAIGHT TO "Phoenix Secure Core Technology Setup".

REINSTALL GTA V

Hi time to visit a computer tech with it.