Installing NICs

I have just reformatted and installed a clean version of NT SBS. On installing the adaptors via network in control panel. I note that the nics are numbered [4] and [5]. The previous version of SBS before the reformat had 3 nics numbered [1], [2] and [3]. Why has this happened?

On inspecting the event log after instalation and before the server was connected to the lan, a brower election was reported. Why?

I am using an Intel dual port nic.