NIC card settings in a dual boot system

I have recently installed a second copy of Windows XP on the same Computer on a different partition. I am unsure how I should set up the NIC card in the latest version of WinXP – I have given the computer a different name on each partition but maybe this confuses Windows as I cannot make a connection to the network or to the Internet using a Staic IP address. Obviously the mac address of the NIC is the same for both partitions. Should I be using the same Computer name and the same static IP address regardless of which operating system version I am logging into, or should I be changing 1 or both systems to have a different Computer name and/or IP address.Advice would be very welcome.