jbworrill: Go to control panel, then networks.
I believe it's adapters, then pick the one you want to assign the IP address for. I picked my 1st nic because that's what XP set up as the one I don't use with my cable modem. Right clicked it, went to properties. Then you'll see different protocols there, go to tcp/ip and do properties on that. You'll see some radio buttons there, change Automatic IP detection/DHCP or whatever it is to "Assign IP manually" and change it to something like 192.168.0.1
To test it, reboot and when I did that my startup sound started while it was loading, not 30 seconds after the desktop was there.