Your IP is set in all version of windows in the TCP/IP settings of your network. Go to your control panel and open the network applet, or right click "My Network Places" and choose properties. I think that then shows you the various connections set up on your computer. Right click on the one you're changing and choose properties again, then choose TCP/IP and again, hit the properties button. It should be self-explanatory then.
EP, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS