Most wireless networks use a wireless router, base station, or access point. These are called infrastructure networks; all communications on the network are between the computers and the access point. You can also tie a group of computers together without an access point, and this is called an ad hoc network. In this type of network, the computers talk directly to each other. A common scenario for using an ad hoc network is where a group of business people connect together at a conference table in order to share files and information.

You can set up an ad hoc wireless network between two or more Windows computers so that you can share files without requiring any additional hardware. This can be handy at a meeting, in a conference room, at home, or when working with a client-anywhere that you want to connect computers to share files and printers.

One computer needs to "create" the network. Then, any others can join it using the standard connection process. To create an ad hoc network on Windows 7, follow these steps:

1. Click the network icon in the taskbar and select Open Network and Sharing Center.
2. Click Set Up a New Connection or Network, scroll down and select Set Up a Wireless Ad Hoc (Computer-to-Computer) Network, and then click Next twice.
3. Choose and type in a name for your new network. This name will appear in the list of available connections on other computers.
4. Select a security type. If all the computers that need to join the network support WPA2 (Windows 7, Vista, and XP SP3 certainly do), select WPA2-Personal; otherwise select WEP, or if you want no security at all, select No Authentication. (However, because you're almost surely setting up this network to share files, using no security means anyone could connect and possibly see the shared files-it's dangerous!)
5. If you selected WPA2 or WEP, enter a security key.
6. If you might want to reconstruct this network again, at a future meeting perhaps, or if want to you use this as your permanent office or home network, check Save This Network. Finally, click Next.
7. When the setup wizard has finished, click Close. The network will start functioning once other users locate it and connect to it.

To connect to this new ad hoc network, other users can have their OS display a list of available networks and locate the one you created; or, if you elected to save the network profile in step 6, you can give them the setup profile using a removable USB (flash) drive. To terminate an ad hoc network, click the taskbar's network icon, select the ad hoc network, and click Disconnect.