I have a Dell Dimension 5100 (runs Windows XP Media Center Edition), which came with a Radeon X300 graphics card. I thought I needed a better video card to play comp games with, so I bought a Radeon X1600 and installed it myself. Most of the times, my comp is fine, but every once in a while the screen will show small green dots that sort of flicker and the screen will go black. All the wires are plugged in, the monitor is still turned on but is just black. Other programs will continue to run. e.g. I will be playing music on iTunes, the screen will black out, but music will still be playing. Any ideas on what's wrong? Maybe I installed the video card wrong?