I cannot remember exactly the phrases used in Windows XP English version.
You should right click on "Network neighbor" on the desktop and choose "Properties", and a window should pop up and then look for something like "local network" with "LAN" "firewall enabled", and right click it to choose "properties" again.
Now you should see in the middle of pop-up window, there is "Internet protocol (TCP/IP)". Double click it. Now you should be able to change the IP settings.
My suggestion is that you check this exact setting on your notebook and modify the settings according to it, I mean you make the setting exactly the same to your notebook, and unplug the network cable connected to your notebook and connect it to your PC.
After all these, try to access the internet, and tell me what happens.
You should right click on "Network neighbor" on the desktop and choose "Properties", and a window should pop up and then look for something like "local network" with "LAN" "firewall enabled", and right click it to choose "properties" again.
Now you should see in the middle of pop-up window, there is "Internet protocol (TCP/IP)". Double click it. Now you should be able to change the IP settings.
My suggestion is that you check this exact setting on your notebook and modify the settings according to it, I mean you make the setting exactly the same to your notebook, and unplug the network cable connected to your notebook and connect it to your PC.
After all these, try to access the internet, and tell me what happens.