monitor stops showing while booting

Hi
Everything was working just fine, but today when I turned on the computer, it happened. Booting starts, it shows everything in DOS, but when trying to enter to Windows, the monitor turns black and its light starts blinking. But, however, I can hear that the booting goes on and enters into Windows. I even clicked on some icon in the darkness of the monitor and I could hear the sound of CPU trying to open the icon. This computer is on a home network is connected directly to a printer. I tried to print a page from another computer which is also on the same network. It was printed, so the system works, just the monitor stops showing while booting. I tried taking the video card out and resetting it back, but it didn't work. I used another monitor, and no use. I do not know what is going on. Plese help me.