Reset TCP/IP

Windows XP SP2, Vista, Windows 7

The below command resets TCP/IP to its default state under Windows XP SP2 and newer OSes. You will have to use elevated command prompt under Vista/Windows 7:

netsh int ip reset

Note: If you'd like to generate a log file of the changes, append a logfile path to the above command, i.e.: "netsh int ip reset c:\resetlog.txt". Changes will be appended to the end of the log file if it exists.

The above NetShell (netsh) command-line tool resets the following registry branches to their default state:
SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\
SYSTEM\CurrentControlSet\Services\DHCP\Parameters\

Reset Winsock
Windows XP SP2, Vista, Windows 7

Winsock (the Windows Sockets API) defines how software should access network services, especially TCP/IP. It defines a standard interface between TCP/IP client appliactions (such as an FTP client or a web browser) and the unterlying TCP/IP protocolstack.

To repair Winsock and reset it to its default state, start command prompt (elevated command prompt under Vista/Windows 7) and type the following command: 

netsh winsock reset

Note: If you'd like to generate a log file of the changes, append a logfile path to the above command, i.e.: "netsh winsock reset c:\resetlog.txt". Changes will be appended to the end of the log file if it exists.

Reinstall TCP/IP under Windows 2000

You might have to reinstall TCP/IP to help resolve some issues, such as improperly configured bindings, dialup clients that are unable to connect to the RAS server, NIC drivers that do not properly bind to the TCP/IP protocol, etc.

To remove TCP/IP in Windows 2000:

1. Click to clear the TCP/IP check box from all dialup and LAN connections in "Network and Dialup Connections".
2. Install another protocol (NetBEUI or NWlink) to maintain a placeholder for each conneciton.
3. Restart your computer
4. Reinstall TCP/IP, and restart your computer again.

Note: this method is only available under older Windows OSes (pre-XP). Later Windows versions consider the TCP/IP stack a core component of the operating system and disable the uninstall option for the TCP/IP protocol.