To share an Internet connection by using router in Windows Vista

You need a router first
A router is a little box that connects directly to the cable modem or DSL box.  The Internet signal is automatically shared among all the PCs connected to the router.

Internet connection sharing

• ICS is a built in Vista feature that simulates a router.
• Like a hardware router, ICS distributes a single Internet connection to every computer on the net work but unlike a router, it's free.

 You attempt to enable ICS

• Go to Start > control panel > open network > click network and sharing center > press Manage network connections.
• Right click the icon of the network connection you want to share.
• Go to shortcut menu > choose properties authenticate yourself > press the sharing tab. Allow other network users to connect through this computer's Internet connection, and click OK.

                         

• Get a computer first, called the hostcomputer that is connected to the Internet and that has a separate connection to the other computers on your network.
• You enable ICS on the Internet connection. The other computers on your network then connect to the host computer and from there to the Internet through the host computer's shared Internet connection.

HOW TO enable ICS
Enable ICS on your host computer:

• Go to network connections by press the Start button.
• Press control panel > network and Internet >press network and sharing Center >press manage network connections.
• Right click the connection that you want to share>press properties. 
• If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
• Press the Sharing tab > select the Allow other network users to connect through this computer’s Internet connection check box.

Now starts configuration of TCP/IP.
Make sure the local area network (LAN) connection on each network computer is configured to get an IP address automatically. To do this:

• First open the network connections by press the Start button >press control panel press network and Internet >press network and sharing center > press manage network connections.
• Right-click the LAN connection> press properties.
•  If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
• Press Internet Protocol Version 4 (TCP/IPv4) or Internet Protocol Version 6 (TCP/IPv6) then go to Properties.
• Press Obtain an IP address automatically or Obtain an IPv6 address automatically

To verify whether Windows Vista is using Internet Connection Sharing,
You follow these steps:

1. Press the Start button > type services.msc in the Start Search box > press services.msc in the Programs list.
2. If a window appears administrator password or for confirmation > type your password or click Continue.
3. Find the Internet Connection Sharing (ICS) service in the Name column > examine the status for the service in the status column.
4. Windows Vista is using Internet Connection Sharing if the Status column for the service shows Started.

 

Windows Vista having two different ways to share the internet connection, first is by using ICS and in second is using a router However this article described these two methods of sharing the internet connection in Windows Vista in a step by step.