Laptop won't connect to internet through router?

I set up my new linksys n300 router and I can successfully connect to the internet through the Wi-Fi on my iphone but on my laptop, I get an exclamation point symbol. Troubleshooting the problem says its a problem with my access point but seeing as how the Wi-Fi works on my phone, I'm not sure this is the case. How can I fix this?

Make sure you didn't accidentally turn of the external Wi-Fi switch on your laptop.