Windows XP and Windows 7 instructions for using ICS are similar, detailed under How to Share Internet Access (XP) or Share an Internet Connection on Windows 7. If you have a Mac, you can also Share Your Mac's Internet Connection via Wi-Fi. The instructions here share a wired Internet connection (your computer is directly connected to a cable or DSL modem, for example) or a separate 3G cellular data modem on installed on your computer. If you have a wireless Internet connection that you want to share with other devices, you can Turn Your Windows 7 Laptop into a Wi-Fi Hotspot using Connectify.
Here's How:
- Log on to the Windows host computer (the one connected to the Internet) as an Administrator
- Go to Network Connections in your Control Panel by going to Start > Control Panel > Network and Internet > Network and Sharing Center and then click "Manage network connections".
- Right-click your Internet connection that you want to share (e.g., Local Area Connection) and click Properties.
- Click the Sharing tab.
- Check the "Allow other network users to connect through this computer's Internet connection" option. (Note: for the sharing tab to show up, you will need to have two types of network connections: one for your Internet connection and another that the client computers can connect to, such as a wireless adapter.)
- Optional: If you want other network users to be able to control or disable the Internet connection, select that option. This is useful for dial-up network connections; otherwise, it's probably best left disabled.
- You can also optionally allow other network users to use services running on your network, such as a mail or web server, under the Settings option.
- Once ICS is enabled, you can Set Up an Ad Hoc Wireless Network or use newer Wi-Fi Direct technology so the other devices can connect directly to your host computer for Internet access.
Tips:
- Clients that connect to the host computer should have their network adapters set to get their IP address automatically (look in the network adapter properties, under TCP/IPv4 or TCP/IPv6 and click "Obtain an IP address automatically")
- If you create a VPN connection from your host computer to a corporate network, all of the computers on your local network would be able to access the corporate network if you use ICS.
- If you share your Internet connection over an ad hoc network, ICS will be disabled if you disconnect from the ad hoc network, create a new ad hoc network, or log off from the host computer.
What You Need
- a Windows Vista computer connected to the Internet and another network adapter
- client computers that are TCP-IP enabled and capable of an Internet connection
- network adapter for each computer
- modem for the entire network

