It's strange, but this is what is happening on my network. The opposite of the vast majority of problems on the forums around the web, who have packets sent but not received. I have a built-in wireless network on my laptop. I am running windows firewall with normal settings. Other computers on the same network in my house are working right now. Maybe someone can help me?

Can you ping your router from the laptop? Can you ping an external site?
Sorry I am not a windows user so I am not comfortable walking you through the wireless setup. What operating system are you using?

I would try repairing the connection of your wireless adapter. If windows xp, there is a network icon down in your system tray by your clock, just right click and choose repair and it will go through and try to repair the connection. If windows 7, right click on network icon by your clock, and then choose troubleshoot problems and it will try and repair the connection as well. It could just simply be an ip address conflict and usually running repair will flush the dns cache out and refresh your ip address. After you have done this, try pinging the router address or going to external website to see if you are able to access everything OK.