Try these 2 commands:
Manual steps to recover from Winsock2 corruption for Windows Vista users
Winsock corruption can cause connectivity problems. To resolve this issue by using Network Diagnostics in Windows Vista, follow these steps:
Click http://support.microsoft.com/library/images/support/kbgraphics/Public/EN-US/VistaStartButton.jpg
and then click Network. Click Network and Sharing Center. In the Network and Sharing Center box, click Diagnose and Repair.
Note You may also access the Network and Sharing Center in Control Panel.
Reset Winsock for Windows Vista
To reset Winsock for Windows Vista, follow these steps:
Click http://support.microsoft.com/library/images/support/kbgraphics/Public/EN-US/VistaStartButton.jpg
, type cmd in the Start Search box, right-click cmd.exe, click Run as administrator, and then press Continue. Type netsh winsock reset at the command prompt, and then press ENTER. Note If the command is typed incorrectly, you will receive an error message. Type the command again. When the command is completed successfully, a confirmation appears, followed by a new command prompt. Then, go to step 3. Type exit, and then press ENTER.