my hp has a very strange problem. the pc displays a lot of colors like the ones that show on the xbox 360 when it frezees. everything works fine. when i try to play games, i cant before i could do it. and it only works if i install windows 7 it wont work on windows xp because it shows me hard disk error (blue screen). i tried to download a nvidia driver but when i reset the pc it shows me hard disk error and i have to intall windows again. what should i do?