is configured to obtain an IP address automatically. You can do this by clicking on start>control panel and then clicking on the Network connections icon.
Select the connection you use to access the internet and right click on it. Select 'Properties' and then click on the 'general' tab. Now click once on Internet Protocol (TCP/IP) to highlight it and then click the 'Prperties' button on the right. Make sure that 'Obtain an IP address automatically' is selected, and click your way back to the desktop.