As I understand it it's part of the OS that communicates with network services. So although the tcp/ip is OK winsock can become corrupted so the OS can't communicate correctly and the browser shows unable to show this page, or similar. Can become corrupted when uninstalling or installing programs, especially burning software for some reason. The reset command sets it back to default.
WPA2 Hack Latest News: How Secure is your Wi-Fi?