So my desktop computer is totally disabled. What happens is, that everything runs just normal and my monitor recieves signal from my computer (indicated by the yellow light in my monitor, as opposed to the orange light displayed when no signal is detected), but the problem is that my monitor retains the image for about half a second and then goes entirely black. It gets the image back whenever a "diferent" screen is displayed, such as when the Vista loading bars show up or when the Vista logo displays during startup, but again, after half a second or so, it goes entirely black.

I have no idea of what to do or what might be causing it; I tried removing my graphics card and connecting my monitor directly to my motherboard, but nothing changed. Is there anything I may do about it, or do these symptoms lead to a specific part of my computer that could be at fault? If anything, I would like to know what should I change to fix this situation, and it would be awesome to know what could I do to fix it. I would really appreciate your help. Thanks in advance.

Maybe try using a different cable. If the problem continues, try using a different monitor. My bet's on a bad monitor. If neither fixes the problem, then I don't know.