To change the IP address in Windows XP, open the Control Panel (Classic view), then double-click Network Connections.
Alternatively you can click with the right mouse button usually present the Network Neighborhood icon on the desktop or Start menu.
This will open the following:
Double-click the network that you want to change the IP address, the window opened click the Properties button to see this other window:
Here you select, clicking the left mouse button, the Internet Protocol (TCP / IP) and click the Properties button, usually the IP addresses will all be set automatically as an example:
To set a fixed IP address (static), click the Use the following IP address, as listed below in the key number is used 192.168.1.10 with a subnet mask of 255.255.255.0, if the LAN there are 2 other computers, you can assign, for example, addresses 192.168.1.11 and 192.168.1.12 or 192.168.1.20 and 192.168.1.30, always with the same Subnet mask, can not exist on the same network, computer with an IP address identical.
If your network includes a router for the Internet that would normally act as DHCP server, which automatically assigns IP address, gateway and DNS, you can also set the Default Gateway and DNS Server fields in order to take advantage of the Internet, these values may be the IP address of the router, usually 192.168.1.1 or 192.168.1.254 (consult the router manual).
When you click the OK button to confirm your changes and close the window, click again on OK and then Close on, wait a few seconds and the network adapter will be set with the new IP configuration.