Recently got a malware infection which effectively shut down my internet - LAN & WLAN. Tried everything, spent two hours on HP chat with SAHEB C who finally told me I had to do a destructive system restore - back up everything and start from scratch. Unwilling to settle for this expert opinion, I dug a little deeper and discovered a solution.
TCP/IP stack Winsock settings in Windows Vista may get corrupted, causing errors and problems with Internet connectivity. Corrupt Winsock or Windows sockets configuration can be due to a lot of reasons such as installation of a networking software, or due to virus, trojan or malware infection, or sometime even due to disinfection of spyware by security software.
When Winsock corrupts, the networking errors that you may face include unable to surf the Internet with "Page cannot be displayed" error message in Internet Explorer or AOL even though the DSL/ADSL/cable Internet connection is connected. Sometimes, Windows Firewall/Internet Connection Sharing (ICS) service is terminated as well.
To repair and reset the Windows Vista
1.Click on Start button.
2.Type Cmd in the Start Search text box.
3.Press Ctrl-Shift-Enter keyboard shortcut to run Command Prompt as Administrator. Allow elevation request.
4.Type netsh winsock reset in the Command Prompt shell, and then press the Enter key.
5.Restart the computer.
What netsh winsock reset command does are it resets Winsock Catalog to a clean state or default configuration. It removes all Winsock LSP (Layered Service Providers) previously installed, including the potential malfunctioned LSP that causes loss of network packets transmission failure. So all previously-installed LSPs must be reinstalled. This command does not affect Winsock Name Space Provider entries.