|Is your network interface set to get it's TCP/IP settings automatically (DHCP)?|
If not, that could be the problem.
To check, open a command prompt window (ie: Start >> Run >> type cmd and hit Enter) and perform the following command:
Look for "DHCP enabled" and if it's no, then you need to change the interface to DHCP enabled.
If you'd like, post the output of the "ipconfig /all" command in here and we'll have a look. To do that, click on my name above and read my "how-to" guide titled: "Post the output of ipconfig (version 2)" for the steps on how to do that.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.