no connectivity because "the network did not assign a network address to the computer"

We are trying to get network connection to 3 spare computers in our office. We know they can get connection before. But now when we connect them on, they all get the same error "Limited or no connectivity" because "the network did not assign a network address to the computer."

We even tried to unplug a network cable from a in-use computer (which got connection fine), and plug it to one of the 3 computers. But still the same error.

What could possible cause this? All these 3 computers and the one in-use have Novell client runing on them.