Tried rebooting the lappie yet? Are you using WEP on one but not the other? Also, a lot of routers have web interfaces, like http://192.168.0.1 for example (admin/admin for login/pass on a lot of Linksys gear I believe, maybe no login name, just the password). You could log into it via your desktop if the desktop is also on the 192.168.0.x network.