check out threads posted in the Networking Forum.
How had you setup the wireless router; was a range of IP addresses such as 192.168.2.2 - 192.168.2.100?
If all these standard settings are done correctly, the other thing to check is any software firewall running on your laptop. This might also need the same IP address range to be setup in the "trusted" computers (Networks tab). That is what I had to do with 2 different software firewalls.
Do post with more details of your router model and software firewalls. Also if you are running an 802.11g, 802.11b or pre-N/MIMO, will be useful information for us to try to help.