Hello VentiSC and welcome to the forums!
It seems like your Laptop isn't receiving the correct DHCP information from the router....
1. Have you tried to type in ipconfig /release and ipconfig /renew at the command prompt?
2. Have you tried to input a static IP address for your ethernet adapter for this network?
a. Go to Network and Sharing center in Control Panel, change adapter settings (which should be on the left hand side of the screen), right click on your Adapter and select properties.
b. In the Properties box, click on Internet Protocol Version 4, and properties
c. In the Internet Protocol Version 4 properties box, type in an IP address, this IP address should be similar to another device on the network that has internet connection. For example if your XP PC's IP address is 192.168.1.90 and your router's address is 192.168.1.1, you should type in 192.168.1.xxx where xxx is a number between 2 and 254 excluding the 90 of your other PC.
d. Enter the router's address for the default gateway and Preferred DNS Server
e. And hit ok at the end..
Try connecting to the internet after that.
Hope that helps!