Wireless Internet isnt working..?

My Ethernet-connected computers are getting Internet access. My iPhone is connecting properly through wi-fi. My laptop, however, is not. I turned my firewalls off, though they aren't the problem since the Internet will come on for about 10 seconds every few minutes. My connection is showing full bars for service, but there is a yellow exclamation point and it says 'no Internet access'. This is becoming incredibly frustrating. I'm assuming it isn't my router since my iPhone connects fine. And the laptop is a mere year old so I feel like it isn't the internal wireless card either. Does anyone have any clue why I may not be getting Internet access on my laptop?