I'm not an expert like the other guy there, but this is how I fixed my wireless card not connecting to my router under the association failure. Click the reset button on your router(da little black reset button) then take and load your router cd in the new laptop your having the issue with and set the router up through that laptop. Follow the steps the cd tells you too. Afterwards you should be able to connect to the unsecured router. Once you connect go into your router's configuration page online and set all your passwords, mac filter , ect.. Go around to all your other wireless puter's and connect using your new password and router name if you changed it. Remember there's no name for the router once you reset it, all you have to do is put in the password and you should be able to get to the web page.
Good luck and I hope this works for all like it did for me.
