first hook up your internet connection. Make sure that your router/modem is working properly. Then open Internet Explorer.
IE can get 'stuck' (for lack of a better word) and may require you to close the program, and re-open it.
Sometimes settings can be wrong; press "alt", "Tools", "Internet Options", then the "Connections" tab, towards the bottom there should be a "Lan Settings" button. Check the "Automatically detect settings" box, or enter in the correct information if this is on a more interesting network.
Lastly, some viruses will block internet traffic. Try running your antivirus (Microsoft Security Essentials is a good one if you don't have one), or anti-malware (Malwarebytes is also excelent) and see if it catches anything.
Keep us posted on your progress. And good luck!