|I would check MAC filtering and see if it is enabled in your router. If so, you will have to manually add the computer to the MAC address list.|
Also, what operating system are you running. I would try removing the wireless profile in Windows them try reconnecting to your wireless connection.
You would open control panel, then network and sharing center, then manage wireless connections. Remove your saved wireless connection and then try and reconnect. It should prompt you for the WPA passphrase. Enter that and see if it allows you to connect.