Open up the Run command with Administrative permissions and run: Start --> All Programs --> Accessories --> Command Prompt --> Right click and click 'Run as Administrator' (type following command)
netsh wlan set hostednetwork mode=allow ssid=HotspotName key=YourPassword
Set the network adapter with: (type following command)
netsh wlan start hostednetwork
After running the command, "Microsoft Virtual WiFi Miniport Adapter" must appear in your network and sharing settings.
Enable "Allow other network users to connect through this computer's Internet connection" under your Sharing tab, under properties.
Now you are good to connect your phone or other wireless device to your laptop and share internet.
Alternatively, you may use following software to turn Windows 7 into a Wi-Fi hotspot