Screen blacks out before login

[Kazaf]

My screen blacks out today when I tried to turn on my computer, there is a signal "DSUB" at the right upper coner, I can't even press F8 to enter the save mode, and I tried to reboot my PC but still doesnt work... is there anyone can help?

 

[Tmagic650]

Bad video card, video driver or hard drive... Did you download or install anything right before this problem showed up? Laptop or desktop?