Creating computer-to-computer ("ad hoc") WiFi network directly from your computer, without any router.
Windows XP
Make absolutely sure that you have installed Service Pack 3 or later.
Open the Start menu, select Control Panel, select Network Connections, find a connection that corresponds to your WiFi card, right-click it with a mouse and select Properties:
In the Properties dialog select the Wireless Networks tab, check the Use Windows to configure my wireless network settings checkbox, and click the Add... button:
Make up a name for your network and enter it in the Network name (SSID) field. Check the This is a computer-to-computer (ad hoc) network... checkbox. Uncheck the The key is provided for me automatically checkbox. Select Open for the Network Authentication field and WEP for the Data encryption field. Make up a password consisting of 13 ASCII characters (this is important!!!) and enter it in the Network key and Confirm network key fields and click OK:
Your new network should appear in the Preferred networks list. Simply click OK:
Open the wireless network selection dialog. To do this either click on a wireless network connection icon on system tray:
...or open the Start menu, select Control Panel, select Network Connections, find a connection that corresponds to your WiFi card, right-click it with a mouse and select View Available Wireless Networks:
Find your newly created network in a list, click it, and then click the Connect button:
The password confirmation dialog will appear with pre-filled password. Simply click Connect:
The connection progress window will appear. Don't wait for it to disappear, go to your iPhone's Settings, and connect your iPhone to your newly created network (more on this in Step 3 of WiFi File Transfer manual). After that Windows will be able to finish the network activation process. You will see that the process is finished when the Connected label will appear against your new network name in a list: