1. Open Network Connections by clicking the Start button http://windowshelp.microsoft.com/Que...&RenderKey=XML, clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.
2. Right-click the connection that you want to share, and then click Properties. http://windowshelp.microsoft.com/Que...&RenderKey=XML If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
3. Click the Sharing tab, and then select the Allow other network users to connect through this computer’s Internet connection check box.
NoteThe Sharing tab will not be available if you have only one network connection.4. If desired, you can also select the Allow other network users to control or disable the shared Internet connection check box.
5. Optionally, to allow other network users to use services running on your network, click Settings and select the services you want to allow.

When you enable ICS, your local area network (LAN) connection gets a new static IP address and configuration, so you'll need to reestablish any TCP/IP connections between your host computer and the other network computers.