I have an HP Compaq dc 5000 MT. A fews day ago when I boot into windows the screen is dark. I power down the computer and restart and everything is ok. The next day when I turned my computer on it boots up fine, but the screen was dark and green, I double check the cable connection, wiggle it around but no difference. so I decided to Ipurchase a PCI DVI / VGA video card. I installed it, power the computer on but I get nothing on the screen, keep in mind that I also replace the monitor with a new monitor. Currently the computer only works with the onboard video card and the screen is green. I have not make any changes with the BIOS. Please advise.