It seems like you are having DNS problems. First thing I would do is try clearing your DNS cache:
If that does not help, then try changing your DNS servers temporarily to Google’s (184.108.40.206 and 220.127.116.11) just to make sure that the DNS server that you are using is not having problems. To do this on windows 7:
- Open Network and Sharing Center.
- Click “Change Adapter Settings”.
- Find Network Connection that is used to connect to internet (either “Local Area Connection” or “Wireless Connection”), right-click on it and click
- Now in new windows select “Internet Protocol 4 (TCP/IPv4)” and click
- In the new window click the checkbox for “Use the following DNS server addresses:”
- Type in
- Click Ok and close the rest of the windows.
After this is done, check your internet connection and if you can open pages.