Need Help! Laptop not connecting to wireless network

Hi, All of a sudden, my laptop won't see my router or network. The router works fine with the wired devices and even a different wireless laptop. The 'Atheros' Wi-fi thing in my laptop says it's working fine. COULD IT BE THE LITTLE BUTTON THAT SWITCHES FROM NOT WIRELESS TO WIRELESS? It still shows a blue light as if it's working. All I can see that my computer is not connected. It started with not seeing the wireless printer, but the laptop worked online. Now it doesn't see anything. This makes me believe that the issue is with the laptop. Any other diagnostics I should run? I'm wired to the wall right now, but that won't let me print anything.