This error has been driving me crazy. I got it when trying to connect to certain WiFi's, but not all. Surfing the web gave various solutions, none of which worked. I eventually cracked it by accident, so I'm posting it in the hope I might prevent someone else from going insane. It is far too late for me.
Sony bundles all sorts of clever programs on its laptops. It's mostly concerned with multi-media, but one of them concerns us - VAIO Control Center (sic). So go to start/"All Programs" and select it. Now select "Network Connections", then "VAIO Smart Network".
Here be Dragons.
VAIO Smart Network creates "profiles". Click on "Advanced", recognise that stupid dialogue displayed at start-up? Click "Settings" (bet you never thought of going there).
Now select "Profile Settings" from the left panel. Yes, I know this navigation is tortuous, but we are nearly there. From here you can edit one of your profiles, or create a new one. When a new profile is created from the desktop dialogue when it first connects, it defaults everything to the previous settings. It was carrying over a DNS setting I had from another connection, and that was preventing me from connecting. Select the "IP and DNS" tab and ensure that "Obtain an IP address automatically" and "Obtain DNS server address automatically" are both selected (it was the later which screwed me).
The profile is selected by the name of the network. One thing that Sony engineers did not take into account in their design is a name collision. That is, two distinctly different networks having the same name. Many of our training centres have WiFi's, and they all are named the same, however they have different DNS addresses. That allowed me to connect to one training centre successfully, but then fail at all the others because the profile remembered the DNS address from the previous site. Going through the Microsoft Windows network settings did not detect where this was being held, because Sony were causing the problem not Microsoft (for once).
Hope this helps.