As it’s a new laptop, presumably it’s running Vista? If so, I suggest you remove any connections you have made so far and start afresh.
1. Go to Control Panel > Network and Sharing Center > Manage Wireless Networks in the left pane and right-click the network(s) to be removed.
2. Go to Control Panel > Network and Sharing Center > Set up a Connection or Network in the left pane > Manually Connect > Next then key in the SSID, select WEP/WPA and type in the key. You may also want to tick ‘Start this….‘ and ‘Connect even……‘.
If you still getting nowhere, change the channel number in the router setup and type the WEP/WPA key as hexadecimal characters rather than ASCII into the new laptop.