There may be cause when you need to renew or release the IP address in order to obtain new IP address from the DHCP device if you have installed any router and you are using the DHCP you should release the IP address from your Internet provider to get new one to release the IP address you need to click on the Start button and click on the Run option from the start menu and click on the OK and you will see the dialogue box with the IP address and if the computer is having a current IP address just click on the release button to get new one an click on the Renew button for Windows XP and 2003 you need to type ipconfig/release and press enter and after that ipconfig/renew and press the enter key.