See if any of this helps:
It may be that the TCP/IP protocol has been damaged in which case open a Command Prompt window and, at the prompt, type:
NETSH INTERFACE IP RESET RESETLOG.TXT
and press Enter. (note the spaces in the command line). The original prompt will reappear, exit the Command Prompt window and reboot the PC.
To reset Winsock entries use:
NETSH WINSOCK RESET CATALOG
and press Enter. Exit the Command Prompt window and reboot the PC.
Also, try running these commands: