No Internet? Could need a Flush!

Possibily your DNS Cache is corrupted....Windows 7 users......
here is how to fix it:

Start > All Programs > Accessories > Command Prompt. Rt-click on it and ‘Run As Administrator’. Type the following and hit enter: ipconfig /flushdns 

You should be able to see a confirmation dialog window:

Windows IP Configuration. Successfully flushed the DNS Resolver Cache.