I have a Sony Vaio laptop, running Windows 7 Home Premium 64bit, Up until 2 days ago I had absolutely no problem using its wifi and/or staying connected to the Internet. Two days ago, however, while being on Skype, my Internet connection got disconnected unexpectedly. With windows Network Diagnostics,I sometimes get "The DNS server isn't responding", and sometimes "Local Area Connection/Wireless Network Connection doesn't have a valid IP configuration"OR "computer is trying to use a DNS server that is incorrect or doesn't exist." Even with the cable I am not able to connect to the internet so I can't update the network adapter or fix the problem online. Looking at the 'Basic network information and set up connections' (in Control Panel - Network and Sharing Center) I see my laptop (sometimes connected, sometimes however the line between the laptop and the 'unidentified network' has a yellow triangle on it) and I can see the 'internet' with a red X on the connection line between that and the 'unidentified network. When checking the 'Wireless Network Connection Status' it's showing that it's connected, activity's showing 'sent and received bytes' but says 'no Internet access' to both IPv4 and IPv6 connectivity. I read lots of blogs and advice and tried many of those 'fixes' that were recommended, some of which were the following (shorter versions): - unplugging and replugging the power cable to the modem - resetting the wireless router -rolling back driver - obtaining IP address and DNS server address automatically for Internet Protocol V4 and V6 -changing the "Preferred DNS server" to 18.104.22.168. Later repeated it and changed the "Preferred DNS server" to 22.214.171.124 - netsh int ip reset (CMD) - netsh winsock reset (CMD) -reset TCP/IP -disabling IPv6 - clearing browser history - system restore to an earlier point on my laptop After each change I restarted the laptop. None of the above worked. Right now under 'status' it's showing: IPv4 connectivity: no Internet access PIv6 connectivity: no network access I've used this network for a while and this is the first time this problem has occurred. Be it network driver issue or a patch of some sort i may need to download, until i can connect to the internet, I can't fix this problem on my own. In the meanwhile no other computer or phone with wifi in the house has any problem connecting to the Internet. I took it to a computer technician who said I need to reinstall Windows 7. But none of the many blogs here and elsewhere I read even remotely mention that. Is that the only solution? Before I'm messing up the system even more, I wanted to ask the Expert! What am I not doing right in fixing this issue? Any help is greatly appreciated.