I have a Macbook Air I bought in November 2011, v 10.7.4 and I have issues connecting to the internet. Though the wifi symbol shows that I have a strong connection, I have no internet access. The only way to get it is to shut down my laptop, and reset my router by turning the power off and waiting for a bit then turning it back on. I know I don't have a problem with my router/internet access as other users in my flat have no trouble. Anyone have any idea what the trouble is?
Things to check:
From System Preferences > Network
Then Click "Set Service Order"
Drag and drop the WIFI connection to the top of the order list