MacBook Pro doesn't join my wireless router??

After installing some updates, my macbook no longer joins my wireless router. Prior it was working fine...
I have three other notebooks, including an apple that still can get wireless, except for my new macbook p.

Do you think it's my router? I've tried calling Apple Care and going to the Genius bar and no one can figure out the issue. Help!

PS it joins the wireless at the apple store.

I've found the easiest way if you are having connection troubles, is to open System Preferences, then under "Network" go into the airport menu. From here choose "Assist Me" down the bottom, this always seems to fix the connection for me if there are no obvious reasons for it not working in the first place.

You didn't mention which router you have. Try changing your SSID which is the name you gave your router when you first configured it. You might also need to unplug your router and wait a few minutes before plugging it back in.