One of my friends downloaded game from ocean of games and his windows security is blank

First of all , I did not download from ocean of games , he said that his laptop was running slow though he bought it only last year , so I decided to check his laptop , it was super laggy , i went to the windows security, and it was just pure blank , then I saw that he downloaded from ocean of games and disabled his defender , so I download malwarebytes and ran a scan , it saw around 17 detections , i quarantied all of them , what should he do now ???