I have the same problem. I had tried many methods taught on the Internet to fix it for a week, but I couldn’t solve it. Here what I have done to solve the problem (on my Dell with Windows 7). I don’t really understand exactly what I have done that solved the problem, because I barely know anything about computers.
1. Open Network and Sharing Center
2. Click on Change Adapter Settings
3. Right click on your network connection, and then click on Properties
4. Click on the Internet Protocol, and then click on Properties
5. Select Obtain an IP Address Automatically and Obtain DNS Server Address Automatically
6. Click to choose Advanced . . .
7. Choose DNS tab and deselect Register This Connection’s Address in DNS.

I am writing down what I have done in hope it can help you to solve your similar problem.