Microsoft Research had been working on Virtual WiFi feature set for inclusion in Windows 7, but something got lost along the road to release day, and the functionality never officially made it into the OS. Virtual Wi-Fi was crafted in Microsoft’s research group as a way to “virtualize” one wireless card as several separate adapters.
Life to the rescue, folks at Nomadio exploited the half-done feature into a full fledged functioning application. It’s called Connectify, a free application from the company that effectively turns any Windows 7 computer into a virtual WiFi hotspot — letting users wirelessly tether a number of devices to a laptop at location where only an Ethernet jack is available, or even tether a number of laptops together at a coffee shop that chargers for WiFi.
Connectify lets a Windows 7 laptop “tether” other wireless devices to a single Internet connection by effectively turning that PC into a software-based wireless router.
Note: This is not an Ad-hoc connection, rather a full fledged Wifi Hotspot
You can use Windows 7 laptop as a wireless access point for iPhone, for example, and to provide a wireless connection to multiple PCs when only one Ethernet jack was available. Another example, people can use a wireless printer without any setup, which usually requires that you first plug the [wireless] printer into the computer with a USB cable so it can select the network.
Windows 7 is required on the notebook acting as a wireless hotspot, but any wireless-equipped device, including PCs running Windows XP or Vista, or even Mac laptops, can reach the Web through Connectify without any additional software. Connectify also encrypts the traffic to and from the software “hot spot” using WPA2-Personal (AES) encryption.