Well, sounds like you need to find out your default gateway and dns numbers.
Well, if you go to Start>Run>Type 'cmd'>Then type 'ipconfig' it should give you a list of your IP address, subnet mask and default gateway.
Note down all of that.
Then go to Start>Control Panel>Network and Internet Connections>Network Connections
Then find the connection you use for your wireless network, right click it and go to properties. When that's open you should see something called an 'Internet Protocol (TCP/IP)' click on that and click 'properties'.
What you usually see is a blanked out list with 'find this automatically' and such, well, as this doesn't seem to be working click 'use the following ip address' and enter the information you got before.
As for the DNS numbers (two of them), you'll have to ring up your ISP provider and ask for them. Don't worry, it's a question they answer everyday and will know what you're talking about.
After you've filled all the information click ok and hopefully it'll work (if it doesn't you can easily reset it by checking the 'automatically blah blah' box.
