gateway laptop windows7 keeps turning on & off

Uhm what do you mean turning on and off? Do you mean it keeps rebooting and never lets you log in? Do you mean you walk away from it and the computer turns 'on' after a while then turns 'off'? Do you mean when your trying to play BF4 on Ultra settings your computer reboots on your with a blue screen message? Some clarity would help here on what is happening WHEN.