Hey everyone I need some help with my desktop.The problem started awhile ago when my brother was playing his game.One of his little friends came over and asked if he could play outside.So my brother went outside and left my computer running playing one of his games for a good five hours.

Well when I got back the computer's tower was basically "roaring" with heat.I mean it was loud enough for me to hear it before I even got in the room.Well I was about to turn it off and the screen was frozen on his game.I than tried ctrl alt del but was no use it frozen.So I did a hard shut down(holding the power button intill it turned off) and I left it for a couple hours.When I turned it on the power button went green but the screen wasnt responding.

My dad soon bought me a new screen but it didnt work.It wasnt responding to the screens I guess but it still was able to turn on.What exactly is wrong with my desktop?