NIC load balancing

I have a couple servers running windows 2k which have multiple nics. The onboard are 3com 10/100 and pci ones are Intel pro 100. One of them has onboard Intel as well. Right now I have them all connected to the network so that they look like network connection1, connection2 etc. when I ping the server I get the same single ip address. Is there a way to set them up for dynamic load balancing, and a way to check the status? I was told it happened automatically, but now am not so sure. Thanks!