Here’s the mail I got recently when I get this problem again
This issue can occur if the DNS settings are incorrect.
Check if DNS has been configured automatically.
Method 1: See whether setting a static IP address for the LAN adapter helps. Use 208.67.222.222 for DNS server while doing so.
Here’s how:
a) Click Start, type ncpa.cpl and press Enter.
b) Right click on the connection that you use for the local connection, and then clickProperties.
c) Click to select Internet Protocol Version 4 (TCP/IPv4), and then clickProperties.
d) In the Internet Protocol window, change the Preferred DNS server to208.67.222.222
e) In (TCP/IPv4) Properties, select the Validates settings upon exit check box.
f) Click OK twice to complete the modification.
g) Repeat the steps and set the Preferred DNS server to 208.67.220.220 if the above fails.
Method 2: Follow these steps:
Step 1: Clear the DNS cache and check how it works.
Follow the steps mentioned below to flush DNS.
a. Click Start button.
b. Click All Programs, then click on Accessories
c. Right click on the Command Prompt option,
d. On the drop down menu which appears, click on the Run as Administratoroption.
e. Type ipconfig /flushdns in command prompt and hit enter.
Step 2: You can also try to reset the TCP/IP on the system and check:.
How to reset Internet Protocol (TCP/IP)
If that does not help, let’s try to reset the modem.
To do this, follow these steps:
a. Disconnect the cable that connects the computer to the modem.
b. Turn off the modem and the router.
Note : If the modem or the router does not have a power switch, disconnect the power to the modem or to the router.
d. Restart the computer.
e. After your computer has restarted, turn on the modem or the router, connect the cable from the computer to the modem or the router, and restart the computer.
f. Make sure that all network cables are securely connected.