I have a hp 500-277c, here is a link to it (http://support.hp.com/us-en/document/c04074753). The problem is my friend gifted me a copy of dying light game and this computer is really lagging when i am trying to play it. So the question is pretty simple what is the best graphic card i can put into this computer without changing anything else? (i believe it only has 300 watt). I dont want to upgrade anything just want to add a graphic card that hopefully can run this and more. Thank you