and it's worth renewing the laptop address. In case you haven't done this before, here's how:-
1. Click the Start button.
2. Click 'Run' and type: cmd in the text entry field and click OK
3. When the command prompt window appears type: ipconfig /release (note there's a space between 'release' and the \)
4. Press the enter key.
5. Now type: ipconfig /renew (watch that space again)
Most computers that are on a DHCP network (and your is) will automatically restablish a network connection when you do this, and with luck your problem will be solved. It's worth trying, anyway.