Install the hardware
Install network adapters in any computers that need them, or connect them to the computers. (Follow the installation instructions in the information that came with each adapter.)
Set up or verify an Internet connection (optional)
You don't need an Internet connection to set up a network, although most people want to use their network to share an Internet connection. To set up an Internet connection, you need a cable or DSL modem and an account with an Internet service provider (ISP). For more information, see What do I need to connect to the Internet?
If you already have an Internet connection, you just need to verify that the connection is working. To do that, open your web browser and go to a website that you don't usually visit. (If you go to a website that you visit often, some of its webpages might be stored on your computer and will display correctly even if your connection is faulty.) If the website opens and you don't get any error messages, your connection is working.
To share an Internet connection
You can share one Internet connection among two or more network computers. To do that, you can either use an intermediary device, which is a device located between the Internet connection and your computer, or set up Internet Connection Sharing (ICS). Your ISP might charge a fee for multiple Internet connections. Ask your ISP for information about this.
Use an intermediary device. You can use a router or a combined router and modem to share an Internet connection. If you use a router, connect it to both the modem and the computer with the Internet connection, and then verify your Internet connection again. The information that came with the router should include connection instructions. If you use a combined router and modem, plug it into any computer. Check the information that came with the device for more detailed connection instructions.
The router and modem must be turned on to use the Internet connection from any of the computers on your network.
Set up ICS. If you want to share an Internet connection without using a router, you can set up ICS on the computer that's connected to the modem. That computer will need two network adapters: one to connect to the modem and one to connect to the other computer.