Share an Internet Connection

I have three PCs in my house, but only one Internet connection. How can I access the Web from all three PCs at the same time?

There are several approaches, but the best solution is to use a router (preferably one with wireless support). Essentially, you take the cable that goes from your modem to your PC, unplug it from your PC, and plug it into the back of the router. Then you connect all your PCs to your router, either wirelessly or with cables, and then configure your router.

The router also protects the PCs on your network with its built-in firewall, a must-have in an era of viruses, spyware, and bored teenage hackers.
The alternative to a router, useful only if you need a quick-and-dirty solution or can't use a router for some reason, is to use Windows XP's built-in Internet Connection Sharing (ICS) feature. The trick, basically, is to connect one PC (called the "host") simultaneously to the Net and to your local network. Then you set up your other PCs to piggyback, so to speak, on the host PC's Internet connection. Since the host PC needs two network cards, (one for the local network and one for connecting to the Internet), this approach likely won't save you any money or time, for
that matter over using an inexpensive router.

To set up ICS on the host PC, open the Network Connections control panel and select View --> Details. You should have at least two connections listed: one for your Internet connection and one for your workgroup. If not, your network is not ready.

Find your connection for the Internet. In most cases, this connection will be the network adapter connected to your DSL or cable modem. (For connections that require a username and password, use the PPPoE broadband connection you) Right-click the connection icon, select Properties, and choose the Advanced tab. Check the "Allow other network users to connect through this computer's Internet connection" box, and click OK. Back in the Network Connections folder, it should now say "Enabled, Shared" in the Type column.

The next step is to configure each of the other computers on your network to use the shared connection. On each of the other "client" PCs, open the Network Connections control panel, right-click the connection icon corresponding to the network adapter plugged into your workgroup, and select Properties. Choose the General tab, highlight the "Internet Protocol (TCP/IP)" entry in the list, and click the Properties button. In most cases, you'll want to select the "Obtain an IP address automatically" option. If, however, you need static IP addresses, choose the "Use the following IP address" option, and fill out the fields. For the "Default gateway," type the IP address of the PC hosting the shared Internet connection.

That's it! Test your connection on each PC by loading a web page. Of course, for this to work, the host computer must be turned on and connected to the Internet a requirement that makes the router a much better choice for the long haul.