So, the problem is, that my wi-if is working perfectly fine but I can't open any site. Skype and torrent are working too. And this problem only at my MacBook, so iPad works ok with same wifi.
MacBook Pro, OS X Mountain Lion (10.8.2)
What happens when you try ?. Have you tested with a different web browser; or in the Guest or a new User Account ?.
Nothing happens. "Server not found". I tried all browsers and guest.
Safe mode didn't help either
Double-click anywhere in the line of text below on this page to select it, then copy it to the Clipboard by pressing the key combination command-C:
www.google.com
Launch the Network Utility application.
Step 1
Select the Lookup tab and paste into the address field by pressing command-V. Then press return. Post the output that appears below – the text, please, not a screenshot.
Step 2
Select the Ping tab and do the same. Please enter the same input as you did in Step 1. Don't use the output of Step 1 as input to Step 2.
Important Note
Some web browsers and mail clients will automatically convert a domain name such as "www.example.com" to a clickable URL, such as http://www.example.com. That will interfere with the test. If necessary, edit the input in the Network Utility window to remove any added characters.
Can't open any site
