new NIC, will it cause problems?

[S2S-Robert]

The current onboard NIC I'm having might be causing problems. That's why I'm investigating if putting in a 3com NIC will be hard and what complications it might have.

Now there are 4 ip's bound to the onboard NIC, so what will happen if I put in the 3COM and shut down the other NIC in the BIOS?

Will the 3COM NIC automatically take over with the proper IP settings or do I have to configure it after booting?