|ok, well to find out the issue fist of all we will need a little more information..|
1. When you said "Check for new updates" what did windows say.... because if the internet is not working then it should have reported "unable to connect"..?
2. Are any other applications able to access the internet? If you want to test click on the start orb, type in CMD to the run/search box and type in "ping google.co.uk" (without quotations) into the command prompt. Copy the results here
3. How do you connect to the internet? Is it through a wifi/router or through a LAN? And do you use any kind of proxy authentication?
Hopefully with this information we will be able to diagnose the issue more accurately!