Most of the Internet connectivity problems arise out of corrupt Winsock settings. Windows sockets settings may get corrupted due to the installation of a networking software, or perhaps due to Malware infestation. You will be able connect to the Internet, but the packets won't transfer back and forth. And errors such as Page cannot be displayed may occur when using Internet Explorer. This article lists the methods (with links to third-party websites) to reset/repair the Winsock configuration to defaults.

http://www.snapfiles.com/get/winsockxpfix.html