Hi I have owned my macbook air for a couple of days and have been using the internet via my home wi fi perfectly fine. Today i installed itunes and restarted my mac the internet would not work so i entered my internet WPA again and it keeps saying "connection timeout"

Someone suggested to try

Open System Preferences, Click on Network, Select your WiFi on the left and click the Advanced button at the bottom, click the TCP/IP tab and click the Renew DHCP Lease button. Click OK.

Try it again.

but its still not working :/