Screen Problems, I think

I have had my computer for well over a year and it is running windows vista. Recently, I was doing some stuff and my screen began flashing and the colors were all messed up. I continued and then I got a blue screen of death. When I finally returned and rebooted my computer, all i get is alot of dots, my computer won't fully boot, and when i turn the screen on, a get red squares and green lines and finally being frozen with white dots. Anyone got any ideas