Can you be more specific about "accidentally unattached a GeForce 2 Graphics card"? Did you delete the drivers, or take the card OUT of the PC? if you took it out, was the PC ON or OFF at the time? What video card are you using now that you took the GF2 out?
Or did you simply unplug the monitor cable? If you did, have you made sure none of the pins are bent?
Please try to give us more information. From what you have provided thus far, the only answer I can offer is to put the GeForce 2 back in the computer.